/* MarkdownLab — design tokens + component styles */

*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 14px;
  color: var(--text);
  background:
    radial-gradient(60% 80% at 0% 0%, color-mix(in srgb, var(--accent) 6%, transparent), transparent 60%),
    radial-gradient(50% 60% at 100% 100%, color-mix(in srgb, var(--accent-b) 5%, transparent), transparent 65%),
    var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow: hidden;
}
:root[data-theme='light'] body {
  background:
    radial-gradient(60% 80% at 0% 0%, color-mix(in srgb, var(--accent) 5%, transparent), transparent 60%),
    radial-gradient(50% 60% at 100% 100%, color-mix(in srgb, var(--accent-b) 4%, transparent), transparent 65%),
    var(--bg);
}
button { font: inherit; cursor: pointer; }
input, textarea { font: inherit; color: inherit; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Structural tokens — layout must not shift on theme change */
:root {
  --topbar-h: 56px;
  --statusbar-h: 32px;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;

  --font-body: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --font-read: 'Lora', Georgia, 'Times New Roman', serif;

  /* Rendered-markdown text metrics. Single source of truth — the mermaid
     sandbox (#mermaid-sandbox in app.js) and .lightbox__canvas mirror these
     so htmlLabel measurement and render share one font context. */
  --md-body-font-size:   15.5px;
  --md-body-line-height: 1.7;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-snap: cubic-bezier(0.34, 1.56, 0.64, 1);
  --t-fast: 120ms;
  --t-base: 180ms;
  --t-slow: 280ms;
}

:root[data-theme='dark'] {
  --bg:          #0b0d12;
  --bg-elev-1:   #10131a;
  --bg-elev-2:   #161a23;
  --bg-elev-3:   #1c212c;
  --surface:     #0f1219;
  --border:      #242a38;
  --border-strong: #323a4d;
  --text:        #e5e7eb;
  --text-muted:  #9aa3b2;
  --text-dim:    #8892a5;

  --accent:      #10b981;
  --accent-a:    #059669;
  --accent-b:    #0891b2;
  --accent-soft: rgba(16, 185, 129, 0.14);
  --accent-ring: rgba(16, 185, 129, 0.35);

  --success: #22c55e;
  --warning: #f59e0b;
  --danger:  #ef4444;

  --code-bg:     #0f1419;
  --code-border: #243244;
  --code-inline-bg: #1a2332;
  --kbd-bg:      #1a2332;

  --mermaid-bg:  #0f1a1d;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.35);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.5);
}

:root[data-theme='light'] {
  --bg:          #f7f8fb;
  --bg-elev-1:   #ffffff;
  --bg-elev-2:   #ffffff;
  --bg-elev-3:   #f1f3f8;
  --surface:     #ffffff;
  --border:      #e5e7ec;
  --border-strong: #cfd4df;
  --text:        #0f172a;
  --text-muted:  #475569;
  --text-dim:    #64748b;

  --accent:      #0d9488;
  --accent-a:    #059669;
  --accent-b:    #0e7490;
  --accent-soft: rgba(13, 148, 136, 0.1);
  --accent-ring: rgba(13, 148, 136, 0.3);

  --success: #16a34a;
  --warning: #d97706;
  --danger:  #dc2626;

  --code-bg:     #f6f8fa;
  --code-border: #d0d7de;
  --code-inline-bg: #eef1f6;
  --kbd-bg:      #eef1f6;

  --mermaid-bg:  #ffffff;

  --shadow-sm: 0 1px 2px rgba(15,23,42,0.06);
  --shadow-md: 0 4px 12px rgba(15,23,42,0.08);
  --shadow-lg: 0 16px 48px rgba(15,23,42,0.15);
}

:root { color-scheme: dark; }
:root[data-theme='light'] { color-scheme: light; }
body, .topbar, .pane, .pane__header, .statusbar, .dropdown__menu, .editor, .preview, .segmented {
  transition: background-color 180ms ease, border-color 180ms ease, color 180ms ease;
}

body {
  display: grid;
  grid-template-rows: var(--topbar-h) 1fr var(--statusbar-h);
}
/* Explicit grid-row assignments so display:none in focus mode doesn't collapse
   the shell into row 1. */
body > .topbar    { grid-row: 1; }
body > .shell     { grid-row: 2; min-height: 0; }
body > .statusbar { grid-row: 3; }

/* Shell: sidebar | workspace. CSS variable drives resizability. */
.shell {
  --sidebar-width: 280px;
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 0;
  background: var(--bg);
  transition: grid-template-columns 220ms var(--ease-out);
}
.shell[data-sidebar='collapsed'] { grid-template-columns: 0 1fr; }
.shell[data-sidebar='collapsed'] .sidebar { pointer-events: none; opacity: 0; visibility: hidden; transform: translateX(-12px); }

.topbar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 16px;
  gap: 12px;
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 92%, transparent),
      color-mix(in srgb, var(--bg-elev-2) 96%, transparent));
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--border);
  z-index: 10;
  position: relative;
}
.topbar::before {
  content: '';
  position: absolute;
  left: -120px; top: -40px;
  width: 360px; height: 220px;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%);
  filter: blur(28px);
  pointer-events: none;
  opacity: 0.35;
}
:root[data-theme='light'] .topbar::before { opacity: 0.18; }

.topbar__brand { display: flex; align-items: center; gap: 12px; min-width: 0; overflow: hidden; position: relative; z-index: 1; }
.topbar__logo {
  width: 32px; height: 32px; border-radius: 9px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  box-shadow:
    0 1px 0 rgba(255,255,255,0.18) inset,
    0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent),
    0 6px 18px color-mix(in srgb, var(--accent) 35%, transparent);
  transition: transform var(--t-base) var(--ease-out), box-shadow var(--t-base) var(--ease-out);
}
.topbar__logo:hover {
  transform: translateY(-1px) rotate(-2deg);
  box-shadow:
    0 1px 0 rgba(255,255,255,0.22) inset,
    0 0 0 1px color-mix(in srgb, var(--accent) 50%, transparent),
    0 10px 24px color-mix(in srgb, var(--accent) 45%, transparent);
}
.topbar__logo svg rect { fill: transparent; }
/* Column flex so brand + subtitle stack. The visually-hidden <h1> is
   position:absolute and doesn't participate in flex layout. */
.topbar__title {
  min-width: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
  gap: 2px;
}
.topbar__title-brand {
  display: inline-block;
  font-size: 15px; font-weight: 700; letter-spacing: -0.015em;
  margin: 0; color: var(--text);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  background: linear-gradient(180deg, var(--text), color-mix(in srgb, var(--text) 78%, transparent));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.topbar__subtitle {
  display: inline-flex; align-items: center; gap: 6px;
  margin: 0; font-size: 11px; color: var(--text-muted);
  max-width: 100%;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.topbar__subtitle::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 0 color-mix(in srgb, var(--success) 60%, transparent);
  animation: save-pulse 2.4s ease-out infinite;
  flex-shrink: 0;
}
.topbar__subtitle-name {
  color: var(--text);
  font-weight: 500;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar__subtitle-state {
  color: var(--text-muted);
  flex-shrink: 0;
}
.topbar__subtitle-state::before {
  content: '\00b7';
  margin-right: 6px;
  color: var(--text-muted);
  opacity: 0.6;
}
.topbar__subtitle-state[data-state='dirty'] { color: var(--accent); }
.topbar__subtitle-state[data-state='error'] { color: var(--danger, #ef4444); }
@keyframes save-pulse {
  0%   { box-shadow: 0 0 0 0 color-mix(in srgb, var(--success) 50%, transparent); }
  60%  { box-shadow: 0 0 0 6px color-mix(in srgb, var(--success) 0%, transparent); }
  100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--success) 0%, transparent); }
}
@media (prefers-reduced-motion: reduce) {
  .topbar__subtitle::before { animation: none; }
}
.topbar__nav { display: flex; justify-content: center; }
.topbar__actions { display: flex; align-items: center; gap: 8px; justify-content: flex-end; }

.segmented {
  display: inline-flex;
  padding: 3px;
  background: color-mix(in srgb, var(--bg-elev-3) 90%, transparent);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  position: relative;
  box-shadow: 0 1px 0 rgba(255,255,255,0.04) inset, 0 1px 2px rgba(0,0,0,0.08);
}
.segmented__item {
  position: relative;
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px;
  font-size: 12.5px; font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: 0; border-radius: 7px;
  transition: color var(--t-fast) var(--ease-out), transform var(--t-fast) var(--ease-out);
  z-index: 1;
}
.segmented__item > svg {
  opacity: 0.85;
  transition: opacity var(--t-fast) var(--ease-out), transform var(--t-fast) var(--ease-out);
}
.segmented__item:hover { color: var(--text); }
.segmented__item:hover > svg { opacity: 1; }
.segmented__item:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.segmented__item.is-active {
  color: var(--text);
  background: linear-gradient(180deg, var(--bg-elev-1), color-mix(in srgb, var(--bg-elev-1) 88%, var(--accent) 12%));
  box-shadow:
    0 1px 0 rgba(255,255,255,0.08) inset,
    0 1px 3px rgba(0,0,0,0.16),
    0 0 0 1px color-mix(in srgb, var(--accent) 22%, transparent);
}
.segmented__item.is-active > svg { color: var(--accent); opacity: 1; }
:root[data-theme='light'] .segmented__item.is-active {
  box-shadow:
    0 1px 2px rgba(15,23,42,0.06),
    0 0 0 1px color-mix(in srgb, var(--accent) 20%, transparent);
}

.btn {
  position: relative;
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 12px;
  font-size: 12.5px; font-weight: 500;
  white-space: nowrap;
  color: var(--text);
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition:
    background var(--t-fast) var(--ease-out),
    border-color var(--t-fast) var(--ease-out),
    transform var(--t-fast) var(--ease-out),
    box-shadow var(--t-fast) var(--ease-out),
    color var(--t-fast) var(--ease-out);
}
.btn:not(.btn--primary):hover {
  background: var(--bg-elev-2);
  border-color: var(--border-strong);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.12);
}
.btn:active { transform: translateY(0) scale(0.98); }
.btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.btn > svg { transition: transform var(--t-fast) var(--ease-out); }
.btn:hover > svg { transform: scale(1.06); }

.btn--ghost { background: transparent; border-color: transparent; }
.btn--ghost:hover { background: var(--bg-elev-3); border-color: var(--border); box-shadow: none; transform: translateY(-1px); }
.btn--icon { width: 34px; height: 34px; padding: 0; justify-content: center; }
.btn--icon:hover { color: var(--accent); }

.btn--primary {
  color: #fff;
  background: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  border-color: transparent;
  box-shadow:
    0 1px 0 rgba(255,255,255,0.18) inset,
    0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent),
    0 6px 18px color-mix(in srgb, var(--accent) 28%, transparent);
}
.btn--primary::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(180deg, rgba(255,255,255,0.16), transparent 60%);
  pointer-events: none;
  opacity: 0.7;
  transition: opacity var(--t-fast) var(--ease-out);
}
.btn--primary:hover {
  filter: brightness(1.06);
  transform: translateY(-1px);
  box-shadow:
    0 1px 0 rgba(255,255,255,0.22) inset,
    0 0 0 1px color-mix(in srgb, var(--accent) 50%, transparent),
    0 10px 26px color-mix(in srgb, var(--accent) 40%, transparent);
}
.btn--primary:hover::after { opacity: 1; }
.btn--primary svg { color: #fff; stroke: #fff; }

.icon-sun, .icon-moon { display: none; }
:root[data-theme='dark'] .icon-sun { display: block; }
:root[data-theme='light'] .icon-moon { display: block; }

.icon-focus-off { display: none; }
body.is-focus .icon-focus-off { display: block; }
body.is-focus .icon-focus-on { display: none; }

/* Focus mode (our app button) and raw fullscreen (F11) share the same
   chrome-hiding rules. `.is-fs` is toggled by a fullscreenchange listener
   so the rules apply whether the user clicks Focus or just hits F11. */
body.is-focus,
body.is-fs { grid-template-rows: 0 1fr 0; }
body.is-focus .topbar,
body.is-focus .statusbar,
body.is-fs .topbar,
body.is-fs .statusbar { display: none; }
body.is-focus .shell,
body.is-fs .shell { grid-template-columns: 0 1fr; }
body.is-focus .sidebar,
body.is-fs .sidebar { pointer-events: none; opacity: 0; visibility: hidden; }
body.is-focus .tabs,
body.is-fs .tabs { display: none; }
body.is-focus .pane__header,
body.is-fs .pane__header { display: none; }

/* Skip link — WCAG 2.4.1 Bypass Blocks. Off-screen until focused. */
.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 9999;
  padding: 10px 14px;
  background: var(--accent-b);
  color: var(--bg);
  border-radius: 8px;
  font-weight: 600;
  font-size: 13px;
  text-decoration: none;
  transform: translateY(-150%);
  transition: transform 140ms ease-out;
  box-shadow: 0 4px 16px color-mix(in srgb, #000 35%, transparent);
}
.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--accent-b);
  outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
  .skip-link { transition: none; }
}

/* Visually-hidden utility (WebAIM recipe). Keeps the element in the
   a11y tree and rendered DOM for crawlers/screen readers. Both `clip`
   and `clip-path` are needed for full SR coverage. Do NOT replace with
   display:none / visibility:hidden — both drop the a11y node. */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* Visually-hidden file inputs. We do NOT use the `hidden` attribute here:
   in some browsers (Safari, older iOS) `.click()` on a `display:none` input
   is silently dropped, so the native file chooser never opens. Keeping the
   input in the layout but off-screen and excluded from the tab order
   (`tabindex="-1"` in markup) is the reliable cross-browser pattern. */
.sr-file {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  opacity: 0;
  overflow: hidden;
}

/* About modal.
   Visibility contract: JS toggles `hidden` (authoritative, removes from
   a11y tree) and `.is-open` (flips display:flex + animations). */

.about-modal {
  position: fixed; inset: 0;
  display: none;
  align-items: center; justify-content: center;
  background: color-mix(in srgb, #000 55%, transparent);
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  z-index: 500;
  animation: about-fade 180ms ease-out;
  padding: 20px;
}
.about-modal.is-open { display: flex; }
.about-modal[hidden] { display: none !important; }
@keyframes about-fade { from { opacity: 0; } to { opacity: 1; } }

.about-modal__card {
  width: min(720px, 100%);
  max-height: 85vh;
  display: flex; flex-direction: column;
  background: var(--bg-elev-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: about-in 220ms cubic-bezier(0.22, 1, 0.36, 1);
}
@keyframes about-in {
  from { opacity: 0; transform: translateY(8px) scale(0.985); }
  to   { opacity: 1; transform: none; }
}

.about-modal__header {
  display: flex; align-items: center; justify-content: space-between;
  gap: 14px;
  padding: 18px 20px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-elev-2), var(--bg-elev-1));
}
.about-modal__brand {
  display: flex; align-items: center; gap: 12px;
  min-width: 0;
}
.about-modal__mark {
  flex: 0 0 auto;
  filter: drop-shadow(0 2px 8px color-mix(in srgb, var(--accent-b) 24%, transparent));
}
.about-modal__brand-text { min-width: 0; }
.about-modal__brand-text h2 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--text);
  line-height: 1.2;
}
.about-modal__tagline {
  margin: 2px 0 0;
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.01em;
}
.about-modal__close {
  flex: 0 0 auto;
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 7px;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
  cursor: pointer;
}
.about-modal__close:hover {
  color: var(--text);
  background: var(--bg-elev-3);
  border-color: var(--border);
}
.about-modal__close:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: 2px;
}

.about-modal__body {
  padding: 20px 22px 8px;
  overflow-y: auto;
  overscroll-behavior: contain;
}
.about-modal__lede {
  margin: 0 0 20px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--text);
}
.about-modal__lede strong { font-weight: 600; color: var(--text); }

.about-modal__section-title {
  margin: 16px 0 10px;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  font-weight: 600;
}

/* 2-col on desktop, 1-col on mobile. */
.about-modal__features {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 16px;
}
.about-modal__features > li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 10px 12px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  transition: background 150ms ease, border-color 150ms ease;
}
.about-modal__features > li:hover {
  background: var(--bg-elev-3);
  border-color: color-mix(in srgb, var(--accent-b) 30%, var(--border));
}
.about-modal__features > li > svg {
  flex: 0 0 auto;
  margin-top: 1px;
  color: var(--accent-b);
}
.about-modal__features > li > div {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}
.about-modal__features > li strong {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.005em;
}
.about-modal__features > li span {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-muted);
}
.about-modal__features > li code,
.about-modal__faq code {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 1px 4px;
  border-radius: 3px;
  background: color-mix(in srgb, var(--accent-b) 10%, transparent);
  color: var(--text);
}

/* Segmented tablist. Semantics (tablist/tab/tabpanel) live in HTML. */
.about-modal__faq-tabs {
  display: inline-flex;
  padding: 3px;
  margin: 0 0 12px;
  gap: 2px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.about-modal__faq-tab {
  -webkit-appearance: none;
  appearance: none;
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 12px;
  background: transparent;
  border: 0;
  border-radius: 7px;
  font: inherit;
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease;
  user-select: none;
}
.about-modal__faq-tab:hover { color: var(--text); }
.about-modal__faq-tab.is-active {
  background: var(--bg-elev-1);
  color: var(--text);
  box-shadow:
    0 1px 2px color-mix(in srgb, #000 10%, transparent),
    0 0 0 1px var(--border);
  font-weight: 600;
}
.about-modal__faq-tab:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: 2px;
}
.about-modal__faq-tab-count {
  font-size: 10.5px;
  font-weight: 500;
  padding: 1px 6px;
  border-radius: 99px;
  background: color-mix(in srgb, var(--text-muted) 18%, transparent);
  color: var(--text-muted);
  letter-spacing: 0.02em;
  min-width: 16px;
  text-align: center;
}
.about-modal__faq-tab.is-active .about-modal__faq-tab-count {
  background: color-mix(in srgb, var(--accent-b) 18%, transparent);
  color: var(--accent-b);
}

/* Compact accordion — ± indicator + left accent when open. */
.about-modal__faq {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin: 0 0 8px;
  animation: about-faq-fade 180ms ease-out;
}
.about-modal__faq[hidden] { display: none; }
@keyframes about-faq-fade {
  from { opacity: 0; transform: translateY(2px); }
  to   { opacity: 1; transform: none; }
}
.about-modal__faq details {
  border: 1px solid var(--border);
  border-left: 3px solid var(--border);
  border-radius: 8px;
  background: var(--bg-elev-2);
  overflow: hidden;
  transition: background 150ms ease, border-color 150ms ease;
}
.about-modal__faq details[open] {
  background: var(--bg-elev-3);
  border-color: color-mix(in srgb, var(--accent-b) 22%, var(--border));
  border-left-color: var(--accent-b);
}
.about-modal__faq summary {
  list-style: none;
  cursor: pointer;
  padding: 9px 12px 9px 14px;
  padding-right: 34px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text);
  position: relative;
  transition: color 150ms ease;
  user-select: none;
  line-height: 1.4;
}
.about-modal__faq summary::-webkit-details-marker { display: none; }
/* ± indicator: horizontal bar stays, vertical bar rotates + fades on open. */
.about-modal__faq summary::before,
.about-modal__faq summary::after {
  content: "";
  position: absolute;
  right: 14px; top: 50%;
  background: var(--text-muted);
  border-radius: 1px;
  transition: transform 200ms cubic-bezier(0.22, 1, 0.36, 1), background 150ms ease, opacity 150ms ease;
}
.about-modal__faq summary::before {
  width: 10px; height: 1.5px;
  transform: translateY(-50%);
}
.about-modal__faq summary::after {
  width: 1.5px; height: 10px;
  transform: translate(-4.25px, -50%);
}
.about-modal__faq details[open] summary::before,
.about-modal__faq details[open] summary::after {
  background: var(--accent-b);
}
.about-modal__faq details[open] summary::after {
  transform: translate(-4.25px, -50%) rotate(90deg);
  opacity: 0;
}
.about-modal__faq summary:hover { color: var(--text); }
.about-modal__faq summary:hover::before,
.about-modal__faq summary:hover::after { background: var(--text); }
.about-modal__faq summary:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: -2px;
  border-radius: 6px;
}
.about-modal__faq details > p {
  margin: 0;
  padding: 2px 14px 12px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-muted);
  animation: about-faq-answer 220ms ease-out;
}
@keyframes about-faq-answer {
  from { opacity: 0; transform: translateY(-2px); }
  to   { opacity: 1; transform: none; }
}
.about-modal__faq details > p a {
  color: var(--accent-b);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent-b) 40%, transparent);
  transition: border-color 150ms ease;
}
.about-modal__faq details > p a:hover { border-bottom-color: var(--accent-b); }

.about-modal__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 22px;
  border-top: 1px solid var(--border);
  background: var(--bg-elev-2);
}
.about-modal__link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 12.5px;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 7px;
  transition: background 150ms ease, border-color 150ms ease, color 150ms ease;
}
.about-modal__link:hover {
  background: color-mix(in srgb, var(--accent-b) 14%, var(--bg-elev-3));
  border-color: color-mix(in srgb, var(--accent-b) 40%, var(--border));
}
.about-modal__link:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: 2px;
}
.about-modal__meta {
  font-size: 11.5px;
  color: var(--text-muted);
  letter-spacing: 0.01em;
}

@media (max-width: 640px) {
  .about-modal { padding: 12px; }
  .about-modal__card { max-height: 92vh; }
  .about-modal__header { padding: 14px 16px; }
  .about-modal__brand-text h2 { font-size: 16px; }
  .about-modal__body { padding: 16px 16px 4px; }
  .about-modal__features { grid-template-columns: 1fr; gap: 8px; }
  .about-modal__faq-tabs { display: flex; width: 100%; }
  .about-modal__faq-tab { flex: 1; justify-content: center; }
  .about-modal__footer {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding: 12px 16px;
  }
  .about-modal__meta { text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  .about-modal,
  .about-modal__card,
  .about-modal__features > li,
  .about-modal__faq,
  .about-modal__faq details > p,
  .about-modal__faq-tab,
  .about-modal__faq summary::before,
  .about-modal__faq summary::after,
  .about-modal__link,
  .about-modal__close {
    animation: none !important;
    transition: none !important;
  }
}

/* Force themed bg + text in fullscreen so Mermaid foreignObject labels
   inherit the correct colour instead of the UA default. */
body:fullscreen {
  background: var(--bg) !important;
  color: var(--text);
  width: 100vw;
  height: 100vh;
  display: grid;
  grid-template-rows: 0 1fr 0;
}
body:fullscreen::backdrop { background: var(--bg); }
body:-webkit-full-screen {
  background: var(--bg) !important;
  color: var(--text);
  width: 100vw;
  height: 100vh;
  display: grid;
  grid-template-rows: 0 1fr 0;
}
body:fullscreen .shell,
body:-webkit-full-screen .shell { grid-template-columns: 0 1fr; }
/* Focus-mode floating glass dock.
   Contains: theme · reading · outline · exit. Fades down while idle,
   wakes on mouse movement near the bottom-right. `body.is-focus .focus-dock`
   is the only state that makes it visible. */
.focus-dock {
  position: fixed; bottom: 20px; right: 20px;
  display: none;
  align-items: center;
  gap: 4px;
  padding: 6px;
  color: var(--text);
  background: color-mix(in srgb, var(--bg-elev-2) 86%, transparent);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  opacity: 0.32;
  transform: translateY(4px);
  transition:
    opacity var(--t-base) var(--ease-out),
    transform var(--t-base) var(--ease-out),
    background var(--t-fast) var(--ease-out),
    border-color var(--t-fast) var(--ease-out),
    box-shadow var(--t-fast) var(--ease-out);
  z-index: 120;
}
body.is-focus .focus-dock { display: inline-flex; }
/* Hide the dock while a lightbox or palette is open so they don't fight
   for screen space / attention in the corner. */
body:has(.lightbox.is-open) .focus-dock,
body:has(.palette.is-open) .focus-dock { display: none; }
.focus-dock:hover,
.focus-dock.is-awake,
.focus-dock:focus-within {
  opacity: 1;
  transform: translateY(0);
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border-strong));
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--accent) 22%, transparent);
}
.focus-dock__btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 6px;
  width: 34px; height: 34px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  border-radius: 999px;
  font-size: 12.5px; font-weight: 500;
  cursor: pointer;
  transition:
    background var(--t-fast) var(--ease-out),
    color var(--t-fast) var(--ease-out),
    transform var(--t-fast) var(--ease-out);
}
.focus-dock__btn:hover { color: var(--text); background: color-mix(in srgb, var(--bg-elev-3) 90%, transparent); }
.focus-dock__btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; color: var(--text); }
.focus-dock__btn[aria-pressed='true'] {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, transparent);
}
.focus-dock__btn--exit {
  width: auto;
  padding: 0 12px 0 10px;
  color: var(--text);
  background: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  box-shadow: 0 1px 0 rgba(255,255,255,0.18) inset;
}
.focus-dock__btn--exit:hover {
  background: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  filter: brightness(1.06);
  color: #fff;
}
.focus-dock__btn--exit .focus-dock__label { color: #fff; }
.focus-dock__label { font-size: 12px; font-weight: 600; letter-spacing: 0.01em; }
.focus-dock__divider {
  width: 1px; height: 18px;
  margin: 0 4px;
  background: var(--border);
}
/* Ensure the sun/moon icons inside the dock follow the existing swap rules. */
.focus-dock .icon-sun, .focus-dock .icon-moon { display: none; }
:root[data-theme='dark']  .focus-dock .icon-sun  { display: inline-block; }
:root[data-theme='light'] .focus-dock .icon-moon { display: inline-block; }
@media (prefers-reduced-motion: reduce) {
  .focus-dock { opacity: 1; transform: none; }
}

.dropdown { position: relative; }
.dropdown__caret { opacity: 0.7; transition: transform 150ms ease; }
.dropdown[data-open='true'] .dropdown__caret { transform: rotate(180deg); }
.dropdown__menu {
  position: absolute; right: 0; top: calc(100% + 6px);
  min-width: 260px;
  background: color-mix(in srgb, var(--bg-elev-2) 96%, transparent);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--accent) 8%, transparent);
  padding: 6px;
  opacity: 0; transform: translateY(-6px) scale(0.98);
  pointer-events: none;
  transition: opacity var(--t-base) var(--ease-out), transform var(--t-base) var(--ease-snap);
  z-index: 30;
}
.dropdown[data-open='true'] .dropdown__menu {
  opacity: 1; transform: translateY(0) scale(1); pointer-events: auto;
}
.dropdown__item {
  display: flex; align-items: center; gap: 10px;
  width: 100%; padding: 9px 10px;
  font-size: 13px; color: var(--text);
  background: transparent; border: 0; border-radius: 7px;
  text-align: left;
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
}
.dropdown__item > svg { color: var(--text-muted); flex-shrink: 0; transition: color var(--t-fast) var(--ease-out); }
.dropdown__item > .dropdown__item-text { display: flex; flex-direction: column; min-width: 0; }
.dropdown__item small { color: var(--text-muted); font-size: 11.5px; margin-top: 2px; }
.dropdown__item:hover { background: color-mix(in srgb, var(--accent) 8%, var(--bg-elev-3)); }
.dropdown__item:hover > svg { color: var(--accent); }
.dropdown__item:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: -2px; }
.dropdown__divider { height: 1px; background: var(--border); margin: 4px 2px; }

/* Split button — primary action on the left, dropdown caret on the right. */
.split-btn { position: relative; display: inline-flex; }
.split-btn__main { border-top-right-radius: 0 !important; border-bottom-right-radius: 0 !important; }
.split-btn__caret {
  border-top-left-radius: 0 !important; border-bottom-left-radius: 0 !important;
  padding: 0 6px !important; min-width: 0;
  border-left: 1px solid var(--border) !important;
}
.split-btn__caret .dropdown__caret { opacity: 0.7; transition: transform 150ms ease; }
.split-btn[data-open='true'] .split-btn__caret .dropdown__caret,
.split-btn[data-open='true'] .dropdown__caret { transform: rotate(180deg); }
.split-btn .dropdown__menu { right: 0; }
.split-btn[data-open='true'] .dropdown__menu {
  opacity: 1; transform: translateY(0) scale(1); pointer-events: auto;
}

.switch { display: inline-flex; align-items: center; gap: 7px; cursor: pointer; user-select: none; }
.switch input { position: absolute; opacity: 0; pointer-events: none; }
.switch__track {
  width: 30px; height: 17px;
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 999px;
  position: relative;
  transition: background var(--t-base) var(--ease-out), border-color var(--t-base) var(--ease-out), box-shadow var(--t-base) var(--ease-out);
}
.switch__thumb {
  position: absolute; top: 1px; left: 1px;
  width: 13px; height: 13px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: transform var(--t-base) var(--ease-snap), background var(--t-base) var(--ease-out), box-shadow var(--t-base) var(--ease-out);
}
.switch:hover .switch__track { border-color: var(--border-strong); }
.switch input:checked + .switch__track {
  background: linear-gradient(135deg, color-mix(in srgb, var(--accent-a) 35%, transparent), color-mix(in srgb, var(--accent-b) 35%, transparent));
  border-color: color-mix(in srgb, var(--accent) 60%, transparent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 12%, transparent);
}
.switch input:checked + .switch__track .switch__thumb {
  transform: translateX(13px);
  background: var(--accent);
  box-shadow: 0 0 8px color-mix(in srgb, var(--accent) 50%, transparent);
}
.switch input:focus-visible + .switch__track { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.switch__label { font-size: 12px; color: var(--text-muted); transition: color var(--t-fast) var(--ease-out); }
.switch:hover .switch__label { color: var(--text); }

.workspace {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background: var(--bg);
}

/* Panes row (editor | resizer | preview) sits below the tabs strip.
 * `--toc-offset` shifts the divider left when the outline column is visible
 * so editor width ≈ preview-article width. */
.panes {
  --split: 50%;
  --toc-offset: 0px;
  display: grid;
  grid-template-columns:
    max(180px, calc(var(--split) - var(--toc-offset)))
    6px
    1fr;
  flex: 1;
  min-height: 0;
  min-width: 0;
  background: var(--bg);
}
.panes[data-toc='open'] { --toc-offset: 133px; }  /* ≈ toc/2 + resizer/2 */
.panes[data-view='editor']  { grid-template-columns: 1fr 0 0; }
.panes[data-view='preview'] { grid-template-columns: 0 0 1fr; }
.panes[data-view='editor']  .pane--preview, .panes[data-view='editor']  .resizer { display: none; }
.panes[data-view='preview'] .pane--editor,  .panes[data-view='preview'] .resizer { display: none; }

.pane {
  display: flex; flex-direction: column;
  min-width: 0; min-height: 0;
  background: var(--surface);
}
/* Explicit grid-column pins — when a sibling is display:none, grid
   auto-placement would otherwise pack the visible child into column 1. */
.pane--editor  { grid-column: 1; border-right: 1px solid var(--border); }
.resizer       { grid-column: 2; }
.pane--preview { grid-column: 3; }
.pane__header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 8px 14px;
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 96%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 100%, transparent));
  border-bottom: 1px solid var(--border);
  min-height: 40px;
  position: relative;
}
.pane__tabs { display: flex; gap: 4px; }
.pane__tab {
  position: relative;
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 11px;
  font-size: 12px; font-weight: 500;
  color: var(--text-muted);
  border-radius: 6px;
  letter-spacing: 0.005em;
}
.pane__tab.is-active {
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  color: var(--text);
}
.pane__tab.is-active > svg { color: var(--accent); opacity: 1; }
.pane__tab > svg { opacity: 0.7; transition: opacity var(--t-fast) var(--ease-out); }
.pane__meta { font-size: 11.5px; color: var(--text-muted); display: flex; align-items: center; gap: 10px; }

.btn--mini {
  padding: 4px 8px;
  font-size: 11.5px;
  font-weight: 500;
  border-radius: 6px;
  gap: 6px;
  height: 24px;
}
.pane__toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  color: var(--text-muted);
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  transition: color 120ms, background 120ms, border-color 120ms;
}
.pane__toggle:hover { color: var(--text); background: var(--bg-elev-3); }
.pane__toggle[aria-pressed='true'] {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  border-color: color-mix(in srgb, var(--accent) 36%, transparent);
}
.pane__toggle[aria-pressed='true']:hover {
  background: color-mix(in srgb, var(--accent) 20%, transparent);
}
.pane__toggle[aria-pressed='false'] {
  color: var(--text-muted);
  text-decoration: line-through;
  text-decoration-color: currentColor;
  text-decoration-thickness: 1px;
}
.pane__toggle[aria-pressed='false'] .pane__toggle-icon {
  opacity: 0.6;
}

.resizer {
  background: var(--border);
  cursor: col-resize;
  position: relative;
  transition: background var(--t-base) var(--ease-out);
}
.resizer:hover, .resizer:focus-visible {
  background: linear-gradient(180deg, var(--accent-a), var(--accent-b));
  outline: none;
  box-shadow: 0 0 16px color-mix(in srgb, var(--accent) 35%, transparent);
}
.resizer::before {
  content: ''; position: absolute; inset: 0; left: -5px; right: -5px;
}
.resizer::after {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 2px; height: 24px;
  background:
    radial-gradient(circle, var(--text-dim) 1.2px, transparent 1.8px) 0 0 / 2px 6px repeat-y;
  opacity: 0.55;
  transition: opacity 150ms ease, background 150ms ease;
  pointer-events: none;
}
.resizer:hover::after, .resizer:focus-visible::after {
  opacity: 1;
  background:
    radial-gradient(circle, #fff 1.4px, transparent 1.8px) 0 0 / 2px 6px repeat-y;
}

.editor__wrap {
  display: grid;
  grid-template-columns: 48px 1fr;
  flex: 1; min-height: 0;
  background: var(--surface);
}
.editor__gutter {
  font-family: var(--font-mono);
  font-size: 13px; line-height: 1.65;
  color: var(--text-dim);
  background:
    linear-gradient(90deg,
      color-mix(in srgb, var(--bg-elev-1) 100%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 92%, transparent));
  border-right: 1px solid var(--border);
  padding: 0 8px 0 0;
  text-align: right;
  overflow: hidden;
  user-select: none;
  position: relative;
}
.editor__gutter-inner {
  position: relative;
  width: 100%;
  will-change: transform;
}
.editor__gutter-num {
  position: absolute;
  right: 8px;
  height: 1.65em;
  line-height: 1.65;
}
.editor__surface {
  position: relative;
  min-height: 0;
  height: 100%;
  overflow: hidden;
  /* Surface owns the bg so the transparent textarea (z:1) reveals the
     mirror's find-highlight spans painted at z:0. */
  background: var(--surface);
}
.editor {
  appearance: none;
  position: absolute;
  inset: 0;
  width: 100%; height: 100%;
  font-family: var(--font-mono);
  font-size: 13px; line-height: 1.65;
  color: var(--text);
  background: transparent; /* see .editor__surface */
  border: 0; outline: 0; resize: none;
  padding: 16px 18px;
  tab-size: 2;
  caret-color: var(--accent);
  white-space: pre-wrap;
  overflow-wrap: break-word;
  word-break: break-word;
  overflow-x: hidden;
  overflow-y: auto;
  z-index: 1;
}
.editor::placeholder { color: var(--text-dim); }
/* Mirror doubles as measurement buffer for scroll-sync and as the
   find-highlight overlay. Typography/padding/wrap must match the
   textarea exactly. Text is transparent — only .editor-hl backgrounds
   paint. Position synced with editor.scrollTop via translate3d. */
.editor__mirror {
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  font-family: var(--font-mono);
  font-size: 13px; line-height: 1.65;
  padding: 16px 18px;
  box-sizing: border-box;
  tab-size: 2;
  white-space: pre-wrap;
  overflow-wrap: break-word;
  word-break: break-word;
  color: transparent;
  pointer-events: none;
  z-index: 0;
  will-change: transform;
}
.editor__mirror > div { min-height: 1.65em; }
/* Find-match highlights. Hue matches mark.find-match so both panes read
   as one UI; inherited transparent text keeps the span invisible. */
.editor__mirror .editor-hl {
  background: color-mix(in srgb, var(--warning) 38%, transparent);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--warning) 50%, transparent);
  border-radius: 2px;
}
.editor__mirror .editor-hl--active {
  background: var(--accent);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 75%, transparent);
}

.preview__layout {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: row;
  min-width: 0;
}
.preview__wrap {
  flex: 1;
  min-width: 0;
  min-height: 0;
  overflow: auto;
  scrollbar-gutter: stable;
}
.preview {
  max-width: 100ch;
  margin: 0 auto;
  padding: 40px 48px 80px;
  color: var(--text);
}

.toc {
  flex: 0 0 260px;
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  background:
    radial-gradient(120% 60% at 100% 0%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 60%),
    linear-gradient(180deg, var(--bg-elev-1), var(--bg));
  border-left: 1px solid var(--border);
  position: relative;
  transition: flex-basis 220ms var(--ease-out),
              border-color 160ms ease,
              opacity 180ms ease;
  z-index: 1;
}
.workspace .toc[data-collapsed='true'] {
  flex-basis: 0;
  border-left-color: transparent;
  pointer-events: none;
  opacity: 0;
  overflow: hidden;
}

.toc__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 12px 14px 10px 18px;
  border-bottom: 1px solid var(--border);
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 96%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 88%, transparent));
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 1;
}
.toc__title {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.toc__title svg { color: var(--accent); opacity: 0.85; }
.toc__close {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px; height: 24px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  transition: color 150ms ease, background 150ms ease, border-color 150ms ease;
}
.toc__close:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border); }
.toc__close:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

.toc__nav {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  padding: 12px 12px 16px 18px;
  /* Hide scrollbar — JS centre-follow drives scrollTo() directly.
     No scroll-behavior to avoid double-smoothing. */
  scrollbar-width: none;
  -ms-overflow-style: none;
  position: relative;
}
.toc__nav::-webkit-scrollbar { width: 0; height: 0; display: none; }
.toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.toc__list::before {
  content: '';
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--border);
  border-radius: 1px;
}

/* Single sliding active-link indicator. Composited transform + height
   glides between links in 300ms without overshoot. */
.toc__indicator {
  position: absolute;
  left: 6px;
  top: 0;
  width: 2px;
  height: 0;
  background: linear-gradient(180deg, var(--accent-a), var(--accent-b));
  border-radius: 2px;
  transform: translateY(0);
  opacity: 0;
  pointer-events: none;
  box-shadow: 0 0 10px color-mix(in srgb, var(--accent) 55%, transparent);
  transition:
    transform 300ms cubic-bezier(0.4, 0, 0.2, 1),
    height 300ms cubic-bezier(0.4, 0, 0.2, 1),
    opacity 180ms linear;
  will-change: transform, height;
}
.toc__indicator.is-visible { opacity: 1; }

.toc__item { margin: 0; }
.toc__link {
  position: relative;
  display: block;
  padding: 5px 10px 5px 14px;
  margin-left: -2px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--text-muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  border-radius: 0 6px 6px 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color 160ms ease, background 160ms ease, transform 160ms ease;
}
.toc__link:hover {
  color: var(--text);
  background: color-mix(in srgb, var(--text) 5%, transparent);
  transform: translateX(1px);
  text-decoration: none;
}
.toc__link:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: -2px;
}
.toc__link.is-active {
  color: var(--accent);
  font-weight: 600;
  background:
    linear-gradient(90deg,
      color-mix(in srgb, var(--accent) 18%, transparent),
      color-mix(in srgb, var(--accent) 6%, transparent));
  /* Leave border-left-color alone — .toc__indicator is the sliding
     active affordance, and a per-link border would fight its transition. */
}
.toc__link img,
.toc__link .emoji {
  width: 14px; height: 14px;
  vertical-align: -2px;
  margin-right: 4px;
}

.toc__item--l1 > .toc__link { padding-left: 14px; font-weight: 600; color: var(--text); letter-spacing: -0.005em; }
.toc__item--l2 > .toc__link { padding-left: 14px; }
.toc__item--l3 > .toc__link { padding-left: 28px; }
.toc__item--l4 > .toc__link { padding-left: 42px; font-size: 12px; }
.toc__item--l5 > .toc__link { padding-left: 56px; font-size: 11.5px; color: var(--text-dim); }
.toc__item--l6 > .toc__link { padding-left: 70px; font-size: 11.5px; color: var(--text-dim); }

.toc[data-empty='true'] {
  flex-basis: 0;
  border-left-color: transparent;
  pointer-events: none;
  opacity: 0;
  overflow: hidden;
}

.panes[data-view='editor'] .toc { display: none; }

/* ──────────────────────────────────────────────────────────────────────────
 * TOC as a slide-in drawer (≤1100px): tablet + mobile.
 *
 * Below 1100px the split-view TOC column would squeeze the preview; instead
 * we promote it to a fixed right-side drawer that slides in when the user
 * taps the "Outline" button. The button in the preview header now meaningfully
 * toggles visibility at every size.
 *
 *   · Open state  → toc[data-collapsed='false'] translates into view
 *   · Closed state → translated off-screen to the right
 *   · Scrim       → .toc-scrim (injected by app.js), click-to-close
 *   · ESC to close, click-on-link to close (handled in app.js)
 * ────────────────────────────────────────────────────────────────────────── */
@media (max-width: 1100px) {
  /* Detach from the flex row so the preview reclaims the full width. */
  .preview__layout { position: relative; }

  /* Override the editor-view hide rule — in drawer mode the TOC is a
     fixed-position overlay, not part of the pane layout, so it should be
     available regardless of which pane is foregrounded. */
  .panes[data-view='editor'] .toc { display: flex; }

  .toc {
    position: fixed;
    top: var(--topbar-h);
    bottom: var(--statusbar-h);
    right: 0;
    width: min(320px, 88vw);
    flex: none;
    z-index: 60;
    border-left: 1px solid var(--border);
    box-shadow: -24px 0 60px -20px rgba(0, 0, 0, 0.45);
    transform: translateX(100%);
    transition:
      transform 260ms cubic-bezier(0.32, 0.72, 0, 1),
      opacity 200ms var(--ease-out);
    opacity: 1;                     /* keep visible; we translate instead */
    will-change: transform;
  }
  :root[data-theme='light'] .toc {
    box-shadow: -24px 0 60px -20px rgba(15, 23, 42, 0.18);
  }

  /* OPEN state: any view-mode, any data-empty. The outline button controls
     collapsed; if the TOC has no headings we still hide for cleanliness. */
  .toc[data-collapsed='false'] {
    transform: translateX(0);
  }
  .toc[data-collapsed='true'],
  .toc[data-empty='true'] {
    transform: translateX(100%);
    pointer-events: none;
  }
  /* Even when collapsed, keep it mounted so the open transition plays. */
  .workspace .toc[data-collapsed='true'] {
    flex-basis: unset;
    opacity: 1;
    overflow: hidden;
  }

  /* Scrim (injected by app.js as .toc-scrim). Mirrors the sidebar drawer. */
  .toc-scrim {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.42);
    backdrop-filter: blur(3px) saturate(110%);
    -webkit-backdrop-filter: blur(3px) saturate(110%);
    z-index: 55;
    opacity: 0;
    pointer-events: none;
    transition: opacity 220ms var(--ease-out);
    will-change: opacity;
  }
  .toc-scrim.is-open {
    opacity: 1;
    pointer-events: auto;
  }

  /* When the drawer is open on touch devices, lock body scroll so users
     are clearly interacting with the outline rather than rubber-banding
     the preview underneath. */
  body.is-toc-drawer-open {
    overflow: hidden;
    touch-action: none;
  }

  /* Close button is the primary dismissal on touch — make it a bit larger. */
  .toc__close {
    width: 32px;
    height: 32px;
  }

  /* Header is a bit taller for touch ergonomics. */
  .toc__header {
    padding: 14px 14px 12px 18px;
    min-height: 48px;
  }

  /* Touch-friendly link rows. */
  .toc__link {
    padding-top: 9px;
    padding-bottom: 9px;
    font-size: 13.5px;
  }
}

/* Small phones: take the full right edge with a modest left gap. */
@media (max-width: 560px) {
  .toc {
    width: min(340px, 92vw);
  }
}

@media (prefers-reduced-motion: reduce) {
  .toc, .toc__link, .toc__nav, .toc__indicator, .toc-scrim { transition: none; scroll-behavior: auto; }
}
.preview.is-reading {
  font-family: var(--font-read);
  font-size: 16.5px;
  line-height: 1.75;
  max-width: 72ch;
  margin: 0 auto;
  padding: 56px 48px 96px;
}
.preview.is-reading h1,
.preview.is-reading h2,
.preview.is-reading h3,
.preview.is-reading h4 { font-family: var(--font-read); }

.statusbar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 14px;
  font-size: 11.5px;
  color: var(--text-muted);
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 100%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 92%, transparent));
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--border);
  z-index: 5;
}
.statusbar__group { display: flex; align-items: center; gap: 12px; }
.statusbar__group--center { justify-content: center; gap: 16px; }
.statusbar__group:last-child { justify-content: flex-end; }

.status-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 25%, transparent);
  transition: background var(--t-base) var(--ease-out), box-shadow var(--t-base) var(--ease-out);
  animation: status-breathe 3s ease-in-out infinite;
}
.status-dot[data-status='busy'] {
  background: var(--warning);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--warning) 25%, transparent);
  animation: status-spin 1.4s linear infinite;
}
.status-dot[data-status='error'] {
  background: var(--danger);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--danger) 25%, transparent);
  animation: none;
}
@keyframes status-breathe {
  0%, 100% { box-shadow: 0 0 0 2px color-mix(in srgb, var(--success) 18%, transparent); }
  50%      { box-shadow: 0 0 0 5px color-mix(in srgb, var(--success) 30%, transparent); }
}
@keyframes status-spin {
  0%   { box-shadow: 0 0 0 2px color-mix(in srgb, var(--warning) 12%, transparent); }
  50%  { box-shadow: 0 0 0 5px color-mix(in srgb, var(--warning) 38%, transparent); }
  100% { box-shadow: 0 0 0 2px color-mix(in srgb, var(--warning) 12%, transparent); }
}
@media (prefers-reduced-motion: reduce) {
  .status-dot { animation: none !important; }
}

.stat {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 2px 4px;
  border-radius: 5px;
  transition: color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out);
}
.stat > svg { color: var(--text-dim); transition: color var(--t-fast) var(--ease-out); }
.stat--mono { font-family: var(--font-mono); color: var(--text-dim); }
.stat--link { color: var(--text-muted); }
.stat--link:hover { color: var(--accent); text-decoration: none; background: color-mix(in srgb, var(--accent) 8%, transparent); }
.stat--link:hover svg { color: var(--accent); }
.statusbar__group--center::before,
.statusbar__group--center::after {
  content: '';
  width: 1px; height: 14px;
  background: var(--border);
  margin: 0 4px;
  opacity: 0.7;
}

.drop-overlay {
  position: fixed; inset: 0;
  background: rgba(11,13,18,0.78);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  display: grid; place-items: center;
  opacity: 0; pointer-events: none;
  transition: opacity var(--t-base) var(--ease-out);
  z-index: 100;
}
:root[data-theme='light'] .drop-overlay { background: rgba(247,248,251,0.78); }
.drop-overlay.is-active { opacity: 1; pointer-events: auto; }
.drop-overlay__card {
  position: relative;
  background:
    radial-gradient(140% 80% at 50% 0%, color-mix(in srgb, var(--accent) 18%, transparent), transparent 60%),
    var(--bg-elev-2);
  border: 2px dashed color-mix(in srgb, var(--accent) 70%, transparent);
  border-radius: var(--radius-xl);
  padding: 48px 72px;
  text-align: center;
  color: var(--text);
  box-shadow:
    0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent),
    var(--shadow-lg);
  transform: scale(0.97);
  transition: transform var(--t-base) var(--ease-snap);
}
.drop-overlay.is-active .drop-overlay__card { transform: scale(1); }
.drop-overlay__card svg {
  color: var(--accent);
  margin-bottom: 12px;
  filter: drop-shadow(0 6px 18px color-mix(in srgb, var(--accent) 40%, transparent));
  animation: drop-bounce 1.6s ease-in-out infinite;
}
@keyframes drop-bounce {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-6px); }
}
@media (prefers-reduced-motion: reduce) {
  .drop-overlay__card svg { animation: none; }
}
.drop-overlay__card h2 { margin: 0 0 6px; font-size: 22px; letter-spacing: -0.01em; }
.drop-overlay__card p { margin: 0; color: var(--text-muted); }

.toast {
  position: fixed; bottom: calc(var(--statusbar-h) + 16px); left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: color-mix(in srgb, var(--bg-elev-2) 92%, transparent);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 16px;
  font-size: 13px; font-weight: 500;
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  opacity: 0; pointer-events: none;
  transition: opacity var(--t-base) var(--ease-out), transform var(--t-base) var(--ease-snap);
  z-index: 200;
  display: flex; align-items: center; gap: 8px;
  max-width: 90vw;
}
.toast.is-show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast[data-variant='success'] {
  border-color: color-mix(in srgb, var(--success) 50%, var(--border));
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--success) 25%, transparent);
}
.toast[data-variant='success']::before {
  content: ''; width: 8px; height: 8px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 30%, transparent);
}
.toast[data-variant='error'] {
  border-color: color-mix(in srgb, var(--danger) 50%, var(--border));
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--danger) 25%, transparent);
}
.toast[data-variant='error']::before {
  content: ''; width: 8px; height: 8px; border-radius: 50%;
  background: var(--danger);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--danger) 30%, transparent);
}

/* Preview typography — markdown body */
.markdown-body {
  font-size: var(--md-body-font-size);
  line-height: var(--md-body-line-height);
  word-wrap: break-word;
}
.markdown-body > *:first-child { margin-top: 0; }
.markdown-body > *:last-child { margin-bottom: 0; }
.markdown-body p { margin: 0 0 16px; }

.markdown-body h1, .markdown-body h2, .markdown-body h3,
.markdown-body h4, .markdown-body h5, .markdown-body h6 {
  margin: 32px 0 12px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.015em;
  scroll-margin-top: calc(var(--topbar-h) + 8px);
}
.markdown-body h1 {
  font-size: 2em;
  padding-bottom: 0.4em;
  border-bottom: 1px solid transparent;
  background-image: linear-gradient(90deg, var(--accent-a), var(--accent-b), transparent 80%);
  background-size: 100% 1px;
  background-position: 0 100%;
  background-repeat: no-repeat;
}
.markdown-body h2 {
  font-size: 1.55em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid transparent;
  background-image: linear-gradient(90deg, color-mix(in srgb, var(--accent) 65%, transparent), transparent 70%);
  background-size: 100% 1px;
  background-position: 0 100%;
  background-repeat: no-repeat;
}
.markdown-body h3 { font-size: 1.3em; }
.markdown-body h3::before {
  content: '';
  display: inline-block;
  width: 4px; height: 0.95em;
  background: linear-gradient(180deg, var(--accent-a), var(--accent-b));
  border-radius: 2px;
  margin-right: 0.5em;
  vertical-align: -0.12em;
  opacity: 0.7;
}
.markdown-body h4 { font-size: 1.1em; }
.markdown-body h5 { font-size: 1em; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.04em; }
.markdown-body h6 { font-size: 0.9em; color: var(--text-muted); }

.markdown-body strong { font-weight: 700; color: var(--text); }
.markdown-body em { font-style: italic; }
.markdown-body del { color: var(--text-muted); }
.markdown-body a {
  color: var(--accent);
  text-decoration: none;
  background-image: linear-gradient(180deg, transparent 92%, color-mix(in srgb, var(--accent) 60%, transparent) 92%);
  background-size: 100% 100%;
  background-repeat: no-repeat;
  transition: background-size var(--t-base) var(--ease-out), color var(--t-fast) var(--ease-out);
}
.markdown-body a:hover {
  text-decoration: none;
  background-image: linear-gradient(180deg, transparent 0%, color-mix(in srgb, var(--accent) 18%, transparent) 0%);
  background-size: 100% 100%;
  color: color-mix(in srgb, var(--accent) 80%, var(--text));
}
.markdown-body hr { height: 1px; border: 0; background: var(--border); margin: 32px 0; }

.markdown-body ul, .markdown-body ol { margin: 0 0 16px; padding-left: 28px; }
.markdown-body li { margin-bottom: 4px; }
.markdown-body li > p { margin-bottom: 8px; }
.markdown-body ul ul, .markdown-body ol ol, .markdown-body ul ol, .markdown-body ol ul { margin-bottom: 0; }
.markdown-body ul > li::marker { color: var(--accent); }
.markdown-body ol > li::marker { color: var(--text-muted); font-variant-numeric: tabular-nums; }

.markdown-body input[type='checkbox'] {
  margin-right: 6px; transform: translateY(1px);
  accent-color: var(--accent);
}
.markdown-body li:has(> input[type='checkbox']) { list-style: none; margin-left: -22px; }

.markdown-body blockquote {
  position: relative;
  margin: 0 0 16px;
  padding: 10px 16px 10px 22px;
  color: var(--text-muted);
  border-left: 3px solid var(--accent);
  background:
    linear-gradient(90deg,
      color-mix(in srgb, var(--accent) 14%, transparent),
      color-mix(in srgb, var(--accent) 4%, transparent) 60%,
      transparent);
  border-radius: 0 8px 8px 0;
}
.markdown-body blockquote > :first-child { margin-top: 4px; }
.markdown-body blockquote > :last-child { margin-bottom: 4px; }
.markdown-body blockquote:not(.markdown-alert)::before {
  content: '“';
  position: absolute;
  top: -6px; left: 6px;
  font-family: 'Lora', Georgia, serif;
  font-size: 38px; line-height: 1;
  color: var(--accent);
  opacity: 0.25;
  pointer-events: none;
}

.markdown-body code:not(pre > code) {
  font-family: var(--font-mono);
  font-size: 0.87em;
  font-weight: 500;
  padding: 2px 7px;
  border-radius: 5px;
  background: linear-gradient(180deg, var(--code-inline-bg), color-mix(in srgb, var(--code-inline-bg) 92%, var(--accent) 8%));
  border: 1px solid var(--code-border);
  color: #fca5a5;
  letter-spacing: -0.005em;
}
:root[data-theme='light'] .markdown-body code:not(pre > code) {
  color: #be185d;
}
.markdown-body a > code:not(pre > code) {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 30%, var(--code-border));
}

.markdown-body pre {
  margin: 0 0 18px;
  padding: 16px 18px;
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--code-bg) 100%, transparent),
      color-mix(in srgb, var(--code-bg) 96%, var(--accent) 4%));
  border: 1px solid var(--code-border);
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.55;
  position: relative;
  box-shadow: 0 1px 0 rgba(255,255,255,0.02) inset;
}
.markdown-body pre:has(.code-lang) { padding-top: 38px; }
.markdown-body pre::before {
  content: '';
  position: absolute;
  left: 0; top: 12px; bottom: 12px;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-a), var(--accent-b));
  border-radius: 2px;
  opacity: 0.45;
}
.markdown-body pre:has(.code-lang)::before { top: 38px; }
.markdown-body pre code {
  font-family: var(--font-mono);
  background: transparent; padding: 0; border: 0;
  color: inherit;
}

.code-lang {
  position: absolute;
  top: 8px; left: 14px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-dim);
  background: color-mix(in srgb, var(--bg-elev-3) 75%, transparent);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 999px;
  opacity: 0.6;
  transition: opacity var(--t-base) var(--ease-out), color var(--t-fast) var(--ease-out);
  pointer-events: none;
  user-select: none;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.markdown-body pre:hover .code-lang { opacity: 1; }

/* Always visible (softer in idle, pops on hover) so touch users can see it. */
.code-copy {
  position: absolute; top: 8px; right: 8px;
  background: color-mix(in srgb, var(--bg-elev-3) 80%, transparent);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 11px; font-weight: 500;
  padding: 4px 10px; border-radius: 999px;
  opacity: 0.55;
  transition:
    opacity var(--t-base) var(--ease-out),
    color var(--t-fast) var(--ease-out),
    border-color var(--t-fast) var(--ease-out),
    background var(--t-fast) var(--ease-out),
    transform var(--t-fast) var(--ease-out);
  font-family: var(--font-body);
  backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px);
  display: inline-flex; align-items: center; gap: 5px;
}
.markdown-body pre:hover .code-copy,
.code-copy:focus-visible { opacity: 1; }
.code-copy:hover {
  color: var(--accent); border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  background: color-mix(in srgb, var(--accent) 10%, var(--bg-elev-2));
  transform: translateY(-1px);
}
.code-copy:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.code-copy.is-copied {
  color: var(--success);
  border-color: color-mix(in srgb, var(--success) 45%, var(--border));
  background: color-mix(in srgb, var(--success) 12%, var(--bg-elev-2));
  opacity: 1;
}

.markdown-body .table-wrap {
  overflow-x: auto;
  margin: 0 0 20px;
  border-radius: 10px;
  border: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(255,255,255,0.02) inset;
}
.markdown-body .table-wrap > table {
  margin: 0;
  border: 0;
}
.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 20px;
  font-size: 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  table-layout: auto;
  overflow: hidden;
}
.markdown-body thead {
  background: linear-gradient(180deg, var(--bg-elev-3), color-mix(in srgb, var(--bg-elev-3) 80%, transparent));
}
.markdown-body thead th {
  font-weight: 600;
  letter-spacing: 0.005em;
  color: var(--text);
}
.markdown-body th, .markdown-body td {
  padding: 9px 14px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
.markdown-body tr:last-child td { border-bottom: 0; }
.markdown-body tbody tr {
  transition: background var(--t-fast) var(--ease-out);
}
.markdown-body tbody tr:hover { background: color-mix(in srgb, var(--accent) 6%, var(--bg-elev-3)); }

/* YAML frontmatter: two-column key/value table matching GitHub's blob
   viewer. Scalars render as text, arrays as pill chips, nested maps as
   sub-tables. Hover highlight is suppressed — it's metadata, not content. */
.markdown-body table.markdown-frontmatter {
  width: 100%;
  margin: 0 0 24px;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 14px;
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  table-layout: auto;
  box-shadow: var(--shadow-sm);
}
.markdown-body table.markdown-frontmatter > tbody > tr > th {
  width: 30%;
  min-width: 130px;
  max-width: 240px;
  padding: 10px 16px;
  text-align: right;
  font-weight: 600;
  font-size: 12.5px;
  letter-spacing: 0.02em;
  color: var(--text-muted);
  background: linear-gradient(180deg, var(--bg-elev-3), color-mix(in srgb, var(--bg-elev-3) 80%, transparent));
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
  /* Keys carry U+200B after _/- (softBreakKey); break-word is a last-resort fallback. */
  overflow-wrap: break-word;
}
.markdown-body table.markdown-frontmatter > tbody > tr > td {
  padding: 10px 16px;
  color: var(--text);
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
  overflow-wrap: anywhere;
}
.markdown-body table.markdown-frontmatter > tbody > tr:last-child > th,
.markdown-body table.markdown-frontmatter > tbody > tr:last-child > td {
  border-bottom: 0;
}
.markdown-body table.markdown-frontmatter > tbody > tr:hover {
  background: transparent;
}

.markdown-body table.markdown-frontmatter--nested {
  margin: 0;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-elev-1);
  font-size: 13px;
  box-shadow: none;
}
.markdown-body table.markdown-frontmatter--nested > tbody > tr > th {
  width: 35%;
  background: var(--bg-elev-3);
  font-size: 12px;
}

.markdown-body .frontmatter-chips {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}
.markdown-body .frontmatter-chip {
  display: inline-block;
  padding: 2px 10px;
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 28%, var(--border));
  border-radius: 999px;
  white-space: nowrap;
  transition: background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
}
.markdown-body .frontmatter-chip:hover {
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  border-color: color-mix(in srgb, var(--accent) 42%, var(--border));
}

.markdown-body img {
  max-width: 100%; height: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-elev-3);
  display: block; margin: 8px 0;
}

.markdown-body kbd {
  display: inline-block; padding: 2px 6px;
  font-family: var(--font-mono); font-size: 0.82em;
  background: var(--kbd-bg);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 4px;
  color: var(--text);
  box-shadow: 0 1px 0 rgba(0,0,0,0.1);
}

.markdown-body .footnotes {
  margin-top: 32px; padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 13.5px; color: var(--text-muted);
}
.markdown-body .footnotes ol { padding-left: 24px; }
.markdown-body .footnotes li { margin-bottom: 6px; }

.markdown-body .hljs { background: transparent !important; padding: 0 !important; }

.markdown-body .mermaid {
  position: relative;
  margin: 0 0 18px;
  padding: 20px;
  background: var(--mermaid-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  text-align: center;
  overflow-x: auto;
  min-height: 80px;
}
.markdown-body .mermaid svg { max-width: 100%; height: auto; display: inline-block; }

/* Mirror `.markdown-body` font context so cloned mermaid SVGs render with
   the same text metrics they were measured under in the sandbox. */
.lightbox__canvas {
  font-size: var(--md-body-font-size);
  line-height: var(--md-body-line-height);
}

/* Descender clip fix — Mermaid sizes each <foreignObject> tight to the
   text baseline, so `y`, `p`, `q`, `g`, `j` tails render *below* the box
   and get cropped. Letting the foreignObject overflow paints descenders
   outside its bounds without shifting the label's centered position.
   Applies to both preview and lightbox canvases. */
:is(.markdown-body .mermaid, .lightbox__canvas) foreignObject {
  overflow: visible;
}

/* Gantt polish — Mermaid's default bars are washed-out on dark backgrounds.
   Selectors cover both the preview wrapper AND the lightbox canvas (which
   clones the SVG out of preview). */
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .task {
  stroke-width: 1.25;
  rx: 4; ry: 4;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .taskText,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .taskTextOutsideRight,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .taskTextOutsideLeft {
  fill: #f1f5f9 !important;
  font-weight: 500;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .sectionTitle {
  fill: #f1f5f9 !important;
  font-weight: 600;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .grid .tick line {
  stroke: #2d3548;
  stroke-opacity: 0.8;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .grid path { stroke: #3b4458; }
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .tick text {
  fill: #94a3b8 !important;
  font-size: 10.5px;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .titleText { fill: #f8fafc !important; }
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .today { stroke: #f87171; stroke-width: 2; }

/* ER diagrams — Mermaid ships light attribute-row fills that make our
   near-white text invisible. Force dark row fills + bright attribute text. */
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.entityBox {
  fill: #059669;
  stroke: #6ee7b7;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.entityLabel {
  fill: #ffffff !important;
  font-weight: 600;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.attributeBoxOdd {
  fill: #1e2533 !important;
  stroke: #475569 !important;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.attributeBoxEven {
  fill: #232a3d !important;
  stroke: #475569 !important;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.attributeBoxOdd text,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.attributeBoxEven text,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.relationshipLabel {
  fill: #f1f5f9 !important;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .er.relationshipLabelBox {
  fill: #1e293b !important;
  stroke: none;
}

/* Node & label text colouring is driven by a luminance-aware post-render
   pass in JS (see applyMermaidContrast in app.js) which inspects each
   node's actual fill and chooses #0f172a or #f8fafc for >= 4.5:1 contrast.
   This handles theme defaults AND user-authored `style X fill:#...`
   directives where blanket white text used to be illegible on light fills.

   The rules below are fallback-only: they apply when the JS pass has not
   (yet) annotated a node (e.g. during initial paint, or for state/sequence
   diagrams that don't emit .node wrappers). They use regular (non-important)
   declarations so the JS-set inline styles always win. */
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.stateGroup text,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.stateGroup .state-title {
  fill: #f8fafc;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.node:not([data-mdlab-contrast]) text,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.node:not([data-mdlab-contrast]) .nodeLabel,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.node:not([data-mdlab-contrast]) .label,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) g.node:not([data-mdlab-contrast]) foreignObject div {
  fill: #f8fafc;
  color: #f8fafc;
}

/* Edge-label pill: slate-800 background + slate-100 text is 12.6:1 AA+.
   Fallback for unannotated labels; JS pass overrides with per-edge values
   when needed (edges inherit page bg). */
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .edgeLabel:not([data-mdlab-contrast]),
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .edgeLabel:not([data-mdlab-contrast]) rect,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .edgeLabel:not([data-mdlab-contrast]) foreignObject div {
  background-color: #1e293b;
  fill: #1e293b;
  color: #f1f5f9;
}
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .edgeLabel:not([data-mdlab-contrast]) span,
:root[data-theme='dark'] :is(.markdown-body .mermaid, .lightbox__canvas) .edgeLabel:not([data-mdlab-contrast]) p {
  color: #f1f5f9;
  background: transparent;
}

.diagram-expand {
  position: absolute;
  top: 10px; right: 10px;
  display: inline-flex; align-items: center; gap: 5px;
  padding: 5px 10px;
  font-size: 11.5px; font-weight: 500;
  color: var(--text-muted);
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  opacity: 0.6;
  box-shadow: var(--shadow-sm);
  transition: opacity 150ms ease, color 150ms ease, background 150ms ease, border-color 150ms ease, transform 120ms ease;
  z-index: 2;
  font-family: var(--font-body);
}
.diagram-expand > span { line-height: 1; }
.markdown-body .mermaid:hover .diagram-expand,
.diagram-expand:focus-visible { opacity: 1; }
.diagram-expand:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border-strong); transform: translateY(-1px); }
.diagram-expand:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
/* Mermaid parse-error card — icon + summary with line number, source
   listing with the offending line marked, and a copy button. */
.markdown-body .mermaid.is-error {
  background: color-mix(in srgb, var(--danger) 6%, var(--bg-elev-2));
  border: 1px solid color-mix(in srgb, var(--danger) 35%, var(--border));
  color: var(--text);
  text-align: left;
  padding: 14px 16px 12px;
  border-radius: 10px;
  position: relative;
}
.mermaid-error__header {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid color-mix(in srgb, var(--danger) 22%, var(--border));
}
.mermaid-error__icon {
  color: var(--danger);
  flex-shrink: 0;
  margin-top: 2px;
}
.mermaid-error__titles {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
  flex: 1;
}
.mermaid-error__titles strong {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}
.mermaid-error__summary {
  font-size: 12px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  line-height: 1.5;
  word-break: break-word;
}
.mermaid-error__source {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  margin: 0 0 10px;
  font-size: 12px;
  line-height: 1.55;
  overflow-x: auto;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  color: var(--text-muted);
}
.mermaid-error__line {
  display: flex;
  align-items: baseline;
  gap: 14px;
  white-space: pre;
}
.mermaid-error__line.is-bad {
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  color: var(--text);
  /* Full-bleed stripe: negate parent's horizontal padding. */
  margin: 0 -12px;
  padding: 0 12px;
  box-shadow: inset 3px 0 0 var(--danger);
}
.mermaid-error__ln {
  color: color-mix(in srgb, var(--text-muted) 65%, transparent);
  user-select: none;
  text-align: right;
  min-width: 2ch;
  flex-shrink: 0;
}
.mermaid-error__line.is-bad .mermaid-error__ln { color: var(--danger); }
.mermaid-error__code { white-space: pre; }
.mermaid-error__copy {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--bg-elev-2);
  color: var(--text-muted);
  font: 500 11px/1 'Inter', system-ui, sans-serif;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: color 120ms ease, border-color 120ms ease, background 120ms ease;
}
.mermaid-error__copy:hover {
  color: var(--text);
  border-color: var(--border-strong, color-mix(in srgb, var(--border) 65%, var(--text-muted)));
}
.mermaid-error__copy:focus-visible {
  outline: 2px solid var(--accent-ring);
  outline-offset: 2px;
}
.mermaid-error__copy.is-copied {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
}

/* Lightbox — pan & zoom viewer */
.lightbox {
  position: fixed; inset: 0;
  display: none;
  background: color-mix(in srgb, var(--bg) 92%, #000);
  backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px);
  z-index: 400;
  flex-direction: column;
  animation: lightbox-in 180ms ease-out;
}
.lightbox.is-open { display: flex; }
@keyframes lightbox-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}
.lightbox__toolbar {
  position: absolute;
  top: 14px; left: 50%;
  transform: translateX(-50%);
  display: flex; align-items: center; gap: 2px;
  padding: 6px 8px;
  background: color-mix(in srgb, var(--bg-elev-1) 82%, transparent);
  backdrop-filter: blur(10px) saturate(140%);
  -webkit-backdrop-filter: blur(10px) saturate(140%);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: var(--shadow-lg);
  z-index: 2;
}
.lightbox__btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease, transform 120ms ease;
}
.lightbox__btn:hover { color: var(--text); background: var(--bg-elev-3); }
.lightbox__btn:active { transform: scale(0.94); }
.lightbox__btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.lightbox__btn--close:hover { color: #fff; background: var(--danger); border-color: var(--danger); }
.lightbox__zoom {
  min-width: 52px; text-align: center;
  font-family: var(--font-mono); font-size: 12px;
  color: var(--text-muted);
  padding: 0 6px;
  user-select: none;
}
.lightbox__sep {
  width: 1px; height: 20px;
  background: var(--border);
  margin: 0 6px;
}
.lightbox__stage {
  position: relative; flex: 1;
  overflow: hidden;
  cursor: grab;
  touch-action: none;
  background:
    radial-gradient(circle at 1px 1px, color-mix(in srgb, var(--border-strong) 50%, transparent) 1px, transparent 0) 0 0 / 24px 24px,
    var(--bg);
}
.lightbox__stage:active { cursor: grabbing; }
.lightbox__canvas {
  position: absolute; left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  /* No will-change/scale — zoom writes SVG width/height attrs directly,
     keeping every level vector-crisp. A GPU layer would cache a single
     rasterization and defeat that. */
  pointer-events: none;
}
.lightbox__canvas svg { display: block; }
.lightbox__hint {
  position: absolute; bottom: 14px; left: 50%;
  transform: translateX(-50%);
  font-size: 11.5px;
  color: var(--text-muted);
  background: color-mix(in srgb, var(--bg-elev-2) 82%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  user-select: none;
  transition: opacity 320ms ease;
}
.lightbox__hint.is-show { opacity: 0.95; }
.lightbox__hint--touch { display: none; }
@media (prefers-reduced-motion: reduce) {
  .lightbox { animation: none; }
}

.markdown-body .katex-display {
  margin: 16px 0;
  overflow-x: auto; overflow-y: hidden;
  padding: 6px 0;
}
.markdown-body .katex { font-size: 1.02em; }

/* GFM alerts ([!NOTE]/[!TIP]/…) — applied to blockquotes by the renderer */
.markdown-body .markdown-alert {
  border-left-width: 4px; border-left-style: solid;
  padding: 12px 16px; margin-bottom: 16px;
  border-radius: 0 10px 10px 0;
  background: var(--accent-soft);
  box-shadow: 0 1px 0 rgba(255,255,255,0.02) inset;
}
.markdown-body .markdown-alert-note     { border-left-color: #3b82f6; background: linear-gradient(90deg, rgba(59,130,246,0.14), rgba(59,130,246,0.04) 70%, transparent); }
.markdown-body .markdown-alert-tip      { border-left-color: #10b981; background: linear-gradient(90deg, rgba(16,185,129,0.14), rgba(16,185,129,0.04) 70%, transparent); }
.markdown-body .markdown-alert-warning  { border-left-color: #f59e0b; background: linear-gradient(90deg, rgba(245,158,11,0.14), rgba(245,158,11,0.04) 70%, transparent); }
.markdown-body .markdown-alert-caution  { border-left-color: #ef4444; background: linear-gradient(90deg, rgba(239,68,68,0.14), rgba(239,68,68,0.04) 70%, transparent); }
.markdown-body .markdown-alert-important{ border-left-color: #8b5cf6; background: linear-gradient(90deg, rgba(139,92,246,0.14), rgba(139,92,246,0.04) 70%, transparent); }
.markdown-body .markdown-alert-title {
  font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em;
  font-size: 12px; margin-bottom: 6px;
  display: flex; align-items: center; gap: 7px;
}
.markdown-body .markdown-alert-note     .markdown-alert-title { color: #93c5fd; }
.markdown-body .markdown-alert-tip      .markdown-alert-title { color: #6ee7b7; }
.markdown-body .markdown-alert-warning  .markdown-alert-title { color: #fcd34d; }
.markdown-body .markdown-alert-caution  .markdown-alert-title { color: #fca5a5; }
.markdown-body .markdown-alert-important .markdown-alert-title { color: #c4b5fd; }
:root[data-theme='light'] .markdown-body .markdown-alert-note     .markdown-alert-title { color: #1d4ed8; }
:root[data-theme='light'] .markdown-body .markdown-alert-tip      .markdown-alert-title { color: #047857; }
:root[data-theme='light'] .markdown-body .markdown-alert-warning  .markdown-alert-title { color: #b45309; }
:root[data-theme='light'] .markdown-body .markdown-alert-caution  .markdown-alert-title { color: #b91c1c; }
:root[data-theme='light'] .markdown-body .markdown-alert-important .markdown-alert-title { color: #6d28d9; }

/* Empty state */
.empty-state {
  display: flex; flex-direction: column; align-items: center;
  text-align: center;
  margin: 10vh auto 0;
  max-width: 560px;
  padding: 0 24px;
  color: var(--text);
  animation: empty-in 360ms var(--ease-out) both;
}
@keyframes empty-in { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.empty-state__art {
  color: var(--accent);
  margin-bottom: 18px;
  filter: drop-shadow(0 10px 28px color-mix(in srgb, var(--accent) 35%, transparent));
  animation: empty-float 5s ease-in-out infinite;
}
@keyframes empty-float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-4px); }
}
@media (prefers-reduced-motion: reduce) {
  .empty-state__art { animation: none; }
}
.empty-state__title {
  margin: 0 0 8px;
  font-size: 26px; font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--accent-a), var(--accent-b));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.empty-state__subtitle {
  margin: 0 0 22px;
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.6;
}
.empty-state__actions {
  display: flex; flex-wrap: wrap; gap: 10px; justify-content: center;
  margin-bottom: 28px;
}
.empty-state__hints {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  list-style: none; padding: 0; margin: 0;
  font-size: 12px; color: var(--text-muted);
  width: 100%;
}
.empty-state__hints li {
  display: inline-flex; align-items: center; gap: 6px;
  justify-content: center;
  padding: 8px 10px;
  background: color-mix(in srgb, var(--bg-elev-2) 70%, transparent);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out), transform var(--t-fast) var(--ease-out);
}
.empty-state__hints li:hover {
  background: var(--bg-elev-3);
  border-color: var(--border-strong);
  transform: translateY(-1px);
}
.empty-state__hints kbd {
  font-family: var(--font-mono); font-size: 10.5px;
  padding: 1px 5px;
  background: var(--kbd-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text);
  box-shadow: 0 1px 0 rgba(0,0,0,0.08);
}
@media (max-width: 560px) {
  .empty-state__hints { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* Shortcut cheatsheet overlay */
.shortcuts {
  position: fixed; inset: 0;
  display: none; align-items: center; justify-content: center;
  background: color-mix(in srgb, #000 55%, transparent);
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  z-index: 500;
  animation: shortcuts-fade 180ms ease-out;
}
.shortcuts.is-open { display: flex; }
@keyframes shortcuts-fade { from { opacity: 0; } to { opacity: 1; } }
.shortcuts__card {
  width: min(640px, 92vw);
  max-height: 80vh;
  display: flex; flex-direction: column;
  background: var(--bg-elev-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: shortcuts-in 220ms cubic-bezier(0.22, 1, 0.36, 1);
}
@keyframes shortcuts-in {
  from { opacity: 0; transform: translateY(8px) scale(0.98); }
  to   { opacity: 1; transform: none; }
}
.shortcuts__header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--bg-elev-2), var(--bg-elev-1));
}
.shortcuts__header h2 {
  margin: 0; font-size: 15px; font-weight: 700; letter-spacing: -0.01em;
  color: var(--text);
}
.shortcuts__close {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 7px;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}
.shortcuts__close:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border); }
.shortcuts__close:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.shortcuts__body {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px 28px;
  padding: 20px 22px;
  overflow-y: auto;
}
.shortcuts__group h3 {
  margin: 0 0 10px;
  font-size: 11.5px;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--text-muted);
  font-weight: 600;
}
.shortcuts__group dl { margin: 0; }
.shortcuts__group dl > div {
  display: flex; justify-content: space-between; align-items: center;
  padding: 6px 0;
  gap: 12px;
  border-bottom: 1px dashed var(--border);
}
.shortcuts__group dl > div:last-child { border-bottom: 0; }
.shortcuts__group dt {
  display: inline-flex; gap: 3px; align-items: center;
  font-size: 12px; color: var(--text-muted);
}
.shortcuts__group dt kbd {
  font-family: var(--font-mono); font-size: 10.5px;
  padding: 2px 6px;
  background: var(--kbd-bg);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 4px;
  color: var(--text);
}
.shortcuts__group dd {
  margin: 0;
  font-size: 12.5px; color: var(--text);
}

.stat--btn {
  display: inline-flex; align-items: center; gap: 5px;
  background: transparent; border: 1px solid transparent;
  color: var(--text-muted);
  padding: 2px 8px;
  border-radius: 6px;
  font: inherit;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}
.stat--btn:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border); }
.stat--btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--border-strong) 75%, transparent);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
  transition: background var(--t-fast) var(--ease-out);
}
::-webkit-scrollbar-thumb:hover {
  background: color-mix(in srgb, var(--accent) 50%, var(--text-dim));
  background-clip: padding-box;
}
::-webkit-scrollbar-corner { background: transparent; }
* { scrollbar-color: color-mix(in srgb, var(--border-strong) 75%, transparent) transparent; scrollbar-width: thin; }

@media (min-width: 961px) and (max-width: 1100px) {
  .topbar { gap: 8px; padding: 0 12px; }
  .topbar__actions { gap: 6px; }
  .topbar__actions .btn { padding: 7px 10px; }
  #btn-palette { padding: 7px 9px; }
  #btn-palette span { display: none; }
  .segmented__item { padding: 6px 10px; }
}

@media (max-width: 960px) {
  .topbar { grid-template-columns: auto 1fr auto; padding: 0 10px; }
  .topbar__brand .topbar__subtitle { display: none; }
  /* Hide text label, keep logo — avoids colliding with centre controls. */
  .topbar__title-brand { display: none; }
  .topbar__actions .btn span { display: none; }
  .topbar__actions .dropdown__trigger span { display: inline; }
  .pane__header { padding: 6px 10px; }
  .preview { padding: 24px 20px 60px; }
}
@media (max-width: 720px) {
  .panes { grid-template-columns: 1fr; grid-template-rows: 1fr; }
  .panes .pane--editor, .panes .resizer { display: none; }
  .panes[data-view='editor'] .pane--editor { display: flex; }
  .panes[data-view='editor'] .pane--preview { display: none; }
  .panes[data-view='split']   .pane--editor { display: none; }
  .statusbar__group--center .stat:nth-child(n+3) { display: none; }
  .segmented__item { padding: 6px 8px; }
  .segmented__item span, .segmented__item + span { display: none; }
}

/* ========================================================================
   SIDEBAR — projects & files tree
   ======================================================================== */

.sidebar {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 96%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 100%, transparent));
  border-right: 1px solid var(--border);
  transition: opacity var(--t-base) var(--ease-out), transform var(--t-base) var(--ease-out), visibility 0s linear 0s;
}

.sidebar__search {
  position: relative;
  display: flex; align-items: center;
  padding: 14px 14px 10px;
  gap: 0;
}
.sidebar__search-icon {
  position: absolute;
  left: 24px;
  width: 16px; height: 16px;
  color: var(--text-dim);
  pointer-events: none;
}
.sidebar__search-input {
  appearance: none;
  width: 100%;
  padding: 9px 12px 9px 38px;
  font: 500 13.5px/1.25 var(--font-body);
  color: var(--text);
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 8px;
  outline: none;
  transition: border-color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out), box-shadow var(--t-fast) var(--ease-out);
}
.sidebar__search-input::placeholder { color: var(--text-dim); }
.sidebar__search-input:hover { border-color: var(--border-strong); }
.sidebar__search-input:focus {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border-strong));
  box-shadow: 0 0 0 3px var(--accent-ring);
  background: var(--bg-elev-1);
}
.sidebar__search-kbd {
  position: absolute;
  right: 22px;
  font: 600 11px/1 var(--font-mono);
  padding: 3px 7px;
  color: var(--text-dim);
  background: color-mix(in srgb, var(--bg-elev-1) 80%, transparent);
  border: 1px solid var(--border);
  border-radius: 5px;
  letter-spacing: 0.02em;
  transition: opacity var(--t-fast) var(--ease-out);
}
.sidebar__search-input:focus ~ .sidebar__search-kbd { opacity: 0; }

.sidebar__header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 14px 6px;
}
.sidebar__title {
  margin: 0;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.sidebar__header-actions { display: inline-flex; gap: 2px; }
.sidebar__icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;
  transition: color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
}
.sidebar__icon-btn > svg { width: 16px; height: 16px; }
.sidebar__icon-btn:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border); }
.sidebar__icon-btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

.sidebar__tree {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 6px 10px 16px;
}

.sidebar__empty {
  padding: 28px 18px 20px;
  text-align: center;
  color: var(--text-muted);
}
.sidebar__empty p { font-size: 13px; line-height: 1.55; margin: 0 0 14px; }
.sidebar__empty button { font-size: 12.5px; }

.project {
  margin: 2px 0 6px;
  border-radius: 8px;
  transition: background var(--t-fast) var(--ease-out);
}
.project.is-drag-over {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 40%, transparent);
}
.project__header {
  position: relative;
  display: flex; align-items: center; gap: 8px;
  padding: 8px 8px 8px 10px;
  font-size: 13px; font-weight: 600;
  color: var(--text);
  background: transparent;
  border: 0;
  border-radius: 7px;
  cursor: pointer;
  width: 100%;
  transition: background var(--t-fast) var(--ease-out);
}
.project__header:hover { background: color-mix(in srgb, var(--bg-elev-3) 80%, transparent); }
.project__header:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: -2px; }

.project__chevron {
  display: inline-flex;
  width: 16px; height: 16px;
  color: var(--text-dim);
  transition: transform var(--t-fast) var(--ease-out);
}
.project.is-collapsed .project__chevron { transform: rotate(-90deg); }

.project__dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--project-color, var(--accent));
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--project-color, var(--accent)) 20%, transparent);
  flex-shrink: 0;
}
.project__name {
  flex: 1; min-width: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  color: var(--text);
  letter-spacing: -0.002em;
  text-align: left;
}
.project__count {
  font-size: 11px; font-weight: 500;
  padding: 2px 7px;
  color: var(--text-dim);
  background: color-mix(in srgb, var(--bg-elev-3) 70%, transparent);
  border-radius: 999px;
}
.project__actions {
  display: inline-flex;
  gap: 2px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-fast) var(--ease-out);
}
.project:focus-within .project__actions { opacity: 1; pointer-events: auto; }
@media (hover: hover) {
  .project:hover .project__actions { opacity: 1; pointer-events: auto; }
}
.project__action {
  display: inline-flex; align-items: center; justify-content: center;
  width: 24px; height: 24px;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  border-radius: 5px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
}
.project__action > svg { width: 13px; height: 13px; }
.project__action:hover { color: var(--text); background: var(--bg-elev-3); }
.project__action:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

.project__files {
  display: flex;
  flex-direction: column;
  padding: 3px 0 6px 12px;
  margin-left: 10px;
  border-left: 1px solid color-mix(in srgb, var(--border) 80%, transparent);
}
.project.is-collapsed .project__files { display: none; }

.file {
  position: relative;
  display: flex; align-items: center; gap: 8px;
  padding: 6px 8px 6px 10px;
  margin: 1px 0;
  font-size: 13px;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;
  transition:
    background var(--t-fast) var(--ease-out),
    color var(--t-fast) var(--ease-out),
    border-color var(--t-fast) var(--ease-out);
}
.file:hover { color: var(--text); background: color-mix(in srgb, var(--bg-elev-3) 70%, transparent); }
.file:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: -2px; }
.file.is-active {
  color: var(--text);
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border-color: color-mix(in srgb, var(--accent) 22%, transparent);
}
.file.is-active .file__icon { color: var(--accent); }
.file.is-drag-over {
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  box-shadow: inset 0 2px 0 var(--accent);
}

.file__icon {
  width: 13px; height: 13px;
  color: var(--text-dim);
  flex-shrink: 0;
}
.file__name {
  flex: 1;
  min-width: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.file__name-input {
  flex: 1;
  min-width: 0;
  padding: 2px 6px;
  font: inherit;
  color: var(--text);
  background: var(--bg-elev-1);
  border: 1px solid color-mix(in srgb, var(--accent) 50%, var(--border-strong));
  border-radius: 5px;
  outline: none;
}
.file__dirty {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--accent);
  flex-shrink: 0;
  box-shadow: 0 0 6px color-mix(in srgb, var(--accent) 60%, transparent);
}
.file__actions {
  display: inline-flex; gap: 1px;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-fast) var(--ease-out);
}
.file:focus-within .file__actions,
.file.is-active .file__actions { opacity: 1; pointer-events: auto; }
@media (hover: hover) {
  .file:hover .file__actions { opacity: 1; pointer-events: auto; }
}
.file__action {
  display: inline-flex; align-items: center; justify-content: center;
  width: 22px; height: 22px;
  color: var(--text-dim);
  background: transparent;
  border: 0;
  border-radius: 5px;
  cursor: pointer;
  transition: color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out);
}
.file__action > svg { width: 12px; height: 12px; }
.file__action:hover { color: var(--text); background: var(--bg-elev-3); }
.file__action:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

/* Search result rows inside the tree. */
.search-results { padding: 4px 0; }
.search-result {
  display: flex; flex-direction: column;
  padding: 8px 10px;
  margin: 2px 0;
  border-radius: 7px;
  cursor: pointer;
  background: transparent;
  border: 0;
  width: 100%;
  text-align: left;
  transition: background var(--t-fast) var(--ease-out);
}
.search-result:hover, .search-result:focus-visible { background: var(--bg-elev-3); outline: none; }
.search-result__name { font-size: 13.5px; font-weight: 500; color: var(--text); line-height: 1.35; }
.search-result__name mark {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  padding: 0 1px;
  border-radius: 2px;
}
.search-result__path { font-size: 11.5px; color: var(--text-dim); margin-top: 3px; line-height: 1.4; }
.search-results__empty {
  padding: 20px 14px;
  text-align: center;
  font-size: 13px;
  color: var(--text-dim);
}

.sidebar__footer {
  display: flex; align-items: center; justify-content: space-between;
  gap: 8px;
  padding: 10px 16px;
  border-top: 1px solid var(--border);
  font-size: 11.5px;
  color: var(--text-dim);
}
.sidebar__storage {
  display: inline-flex; align-items: center; gap: 6px;
  min-width: 0;                 /* flex: allow child truncation */
  max-width: 100%;
  cursor: default;
}
.sidebar__storage svg { width: 13px; height: 13px; color: var(--text-muted); flex: 0 0 auto; }
.sidebar__storage #sidebar-storage-label {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
}
/* Near-quota states — color only; details live in the title tooltip. */
.sidebar__storage[data-storage-state='warn'] { color: var(--warning); }
.sidebar__storage[data-storage-state='warn'] svg { color: var(--warning); }
.sidebar__storage[data-storage-state='critical'] { color: var(--danger); }
.sidebar__storage[data-storage-state='critical'] svg { color: var(--danger); }

.sidebar__resizer {
  position: absolute;
  top: 0; bottom: 0; right: -3px;
  width: 6px;
  cursor: col-resize;
  z-index: 2;
  background: transparent;
  transition: background var(--t-fast) var(--ease-out);
}
.sidebar__resizer:hover,
.sidebar__resizer:focus-visible,
.sidebar__resizer.is-dragging {
  background: linear-gradient(90deg, transparent, color-mix(in srgb, var(--accent) 40%, transparent), transparent);
  outline: none;
}

.topbar__sidebar-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  padding: 0;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
}
.topbar__sidebar-toggle:hover { color: var(--text); background: var(--bg-elev-3); border-color: var(--border); }
.topbar__sidebar-toggle:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }
.topbar__sidebar-toggle[aria-pressed='true'] { color: var(--accent); }

/* ========================================================================
   TABS — open file strip above the editor/preview
   ======================================================================== */

.tabs {
  display: flex;
  align-items: stretch;
  min-height: 34px;
  background:
    linear-gradient(180deg,
      color-mix(in srgb, var(--bg-elev-1) 100%, transparent),
      color-mix(in srgb, var(--bg-elev-1) 92%, transparent));
  border-bottom: 1px solid var(--border);
  position: relative;
  z-index: 2;
}
.tabs__scroll {
  display: flex;
  align-items: stretch;
  flex: 1;
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.tabs__scroll::-webkit-scrollbar { display: none; }

.tab {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 8px 0 14px;
  max-width: 220px;
  min-width: 110px;
  font-size: 12px; font-weight: 500;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  border-right: 1px solid var(--border);
  cursor: pointer;
  position: relative;
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
}
.tab:hover { color: var(--text); background: color-mix(in srgb, var(--bg-elev-2) 60%, transparent); }
.tab:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: -2px; }
.tab.is-active {
  color: var(--text);
  background: var(--surface);
}
.tab.is-active::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-a), var(--accent-b));
  border-radius: 2px 2px 0 0;
}
.tab.is-drop-before::before {
  content: '';
  position: absolute;
  left: -1px; top: 4px; bottom: 4px;
  width: 2px;
  background: var(--accent);
  border-radius: 1px;
}
.tab.is-drop-after::after {
  content: '';
  position: absolute;
  right: -1px; top: 4px; bottom: 4px;
  width: 2px;
  background: var(--accent);
  border-radius: 1px;
  z-index: 1;
}

.tab__icon { color: var(--text-dim); flex-shrink: 0; }
.tab.is-active .tab__icon { color: var(--accent); }
.tab__name {
  flex: 1;
  min-width: 0;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.tab__close {
  display: inline-flex; align-items: center; justify-content: center;
  width: 18px; height: 18px;
  color: var(--text-dim);
  background: transparent;
  border: 0;
  border-radius: 4px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
}
.tab__close:hover { color: var(--text); background: color-mix(in srgb, var(--bg-elev-3) 90%, transparent); }
.tab__close:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 1px; }
.tab__dirty {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 6px color-mix(in srgb, var(--accent) 60%, transparent);
}

.tabs__add {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  border-left: 1px solid var(--border);
  cursor: pointer;
  transition: color var(--t-fast) var(--ease-out), background var(--t-fast) var(--ease-out);
}
.tabs__add:hover { color: var(--accent); background: var(--bg-elev-2); }
.tabs__add:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: -2px; }

.tabs__empty {
  display: inline-flex; align-items: center;
  padding: 0 14px;
  font-size: 12px;
  color: var(--text-dim);
  font-style: italic;
}

/* ========================================================================
   COMMAND PALETTE / quick open
   ======================================================================== */

.palette {
  position: fixed; inset: 0;
  display: none; align-items: flex-start; justify-content: center;
  padding: 12vh 16px 0;
  background: color-mix(in srgb, #000 48%, transparent);
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  z-index: 600;
  animation: palette-fade 140ms ease-out;
}
.palette.is-open { display: flex; }
@keyframes palette-fade { from { opacity: 0; } to { opacity: 1; } }
.palette__card {
  width: min(620px, 94vw);
  max-height: 66vh;
  display: flex; flex-direction: column;
  background: var(--bg-elev-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--accent) 10%, transparent);
  overflow: hidden;
  animation: palette-in 200ms cubic-bezier(0.22, 1, 0.36, 1);
}
@keyframes palette-in {
  from { opacity: 0; transform: translateY(-6px) scale(0.99); }
  to   { opacity: 1; transform: none; }
}
.palette__input-wrap {
  position: relative;
  display: flex; align-items: center;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}
.palette__input-icon { color: var(--text-dim); margin-right: 10px; flex-shrink: 0; }
.palette__input {
  flex: 1;
  padding: 0;
  font: 500 14.5px/1.4 var(--font-body);
  color: var(--text);
  background: transparent;
  border: 0;
  outline: none;
}
.palette__input::placeholder { color: var(--text-dim); }
.palette__hint {
  font: 600 10.5px/1 var(--font-mono);
  padding: 3px 7px;
  color: var(--text-dim);
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.palette__list {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 6px;
  margin: 0;
  list-style: none;
}
.palette-item {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 10px;
  border-radius: 7px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out);
}
.palette-item:hover, .palette-item.is-selected {
  background: color-mix(in srgb, var(--accent) 10%, var(--bg-elev-3));
}
.palette-item.is-selected {
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 30%, transparent);
}
.palette-item__icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px;
  color: var(--text-muted);
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 6px;
  flex-shrink: 0;
}
.palette-item.is-selected .palette-item__icon {
  color: var(--accent);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
}
.palette-item__text {
  flex: 1; min-width: 0;
}
.palette-item__title {
  font-size: 13px; font-weight: 500; color: var(--text);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.palette-item__title mark {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  padding: 0 1px;
  border-radius: 2px;
}
.palette-item__subtitle {
  font-size: 11px; color: var(--text-dim);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
  margin-top: 1px;
}
.palette-item__kind {
  font: 600 9.5px/1 var(--font-mono);
  padding: 3px 7px;
  color: var(--text-dim);
  background: color-mix(in srgb, var(--bg-elev-3) 60%, transparent);
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  flex-shrink: 0;
}
.palette-item__kbd {
  font: 600 10px/1 var(--font-mono);
  padding: 2px 6px;
  color: var(--text-dim);
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 4px;
}

.palette__empty {
  padding: 26px 16px;
  text-align: center;
  color: var(--text-muted);
}
.palette__empty small { color: var(--text-dim); display: block; margin-top: 4px; font-size: 11.5px; }

.palette__footer {
  display: flex; gap: 14px;
  padding: 10px 16px;
  font-size: 11px;
  color: var(--text-dim);
  border-top: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg-elev-1) 60%, transparent);
}
.palette__footer kbd {
  font: 600 10px/1 var(--font-mono);
  padding: 2px 5px;
  margin: 0 2px;
  background: var(--kbd-bg);
  border: 1px solid var(--border);
  border-radius: 3px;
  color: var(--text);
}

/* ========================================================================
   Quick-open trigger button kbd label in topbar
   ======================================================================== */

.btn__kbd {
  font: 600 9.5px/1 var(--font-mono);
  padding: 2px 5px;
  margin-left: 4px;
  color: var(--text-dim);
  background: color-mix(in srgb, var(--bg-elev-1) 60%, transparent);
  border: 1px solid var(--border);
  border-radius: 3px;
  letter-spacing: 0.02em;
}
.btn:hover .btn__kbd { color: var(--text-muted); border-color: var(--border-strong); }

/* ========================================================================
   Responsive: sidebar collapses to overlay drawer below 900px
   ======================================================================== */

@media (max-width: 1100px) {
  .btn__kbd { display: none; }
}

@media (max-width: 960px) {
  .shell { --sidebar-width: 260px; }
}

@media (max-width: 880px) {
  .shell { grid-template-columns: 0 1fr; }
  .sidebar {
    position: fixed;
    top: var(--topbar-h);
    bottom: var(--statusbar-h);
    left: 0;
    width: min(84vw, 320px);
    z-index: 60;
    box-shadow: var(--shadow-lg);
    transform: translateX(-100%);
    visibility: hidden;
    opacity: 0;
    border-right: 1px solid var(--border);
  }
  .shell[data-sidebar='open'] .sidebar {
    transform: translateX(0);
    visibility: visible;
    opacity: 1;
  }
  .sidebar__resizer { display: none; }
  .sidebar-scrim {
    position: fixed;
    top: var(--topbar-h);
    bottom: var(--statusbar-h);
    left: 0; right: 0;
    background: color-mix(in srgb, #000 40%, transparent);
    z-index: 55;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--t-base) var(--ease-out);
  }
  .shell[data-sidebar='open'] .sidebar-scrim { opacity: 1; pointer-events: auto; }
  /* Body-scroll lock for the mobile drawer — paired with the scrim's
     touchmove preventDefault in sidebar.js. */
  body.is-drawer-open {
    overflow: hidden;
    touch-action: none;
  }
}

@media (max-width: 560px) {
  .sidebar { width: 92vw; }
  .palette { padding-top: 6vh; }
  .tab { min-width: 90px; padding: 0 6px 0 10px; }
  .focus-dock { right: 12px; bottom: 12px; padding: 4px; }
  .focus-dock__label { display: none; }
  .focus-dock__btn--exit { width: 34px; padding: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .palette { animation: none; }
  .palette__card { animation: none; }
  .sidebar { transition: none; }
  .shell { transition: none; }
}

@media print {
  .topbar, .statusbar, .pane--editor, .resizer, .pane__header, .toast, .drop-overlay,
  .code-copy, .code-lang, .diagram-expand, .toc,
  .sidebar, .tabs, .focus-dock, .palette, .find-bar { display: none !important; }
  body { overflow: auto; display: block; background: #fff; color: #000; }
  .shell { display: block; grid-template-columns: none; }
  .workspace { display: block; }
  .panes { display: block; }
  .pane--preview { display: block; }
  .preview__wrap { overflow: visible; }
  .preview { max-width: none; padding: 0; color: #000; }
  .markdown-body a { color: #000; border-bottom: none; }
  .markdown-body pre, .markdown-body code:not(pre > code) {
    background: #f5f5f5 !important; border-color: #ddd !important; color: #000 !important;
  }
  .markdown-body blockquote { background: #f5f5f5; color: #333; }
  .markdown-body .mermaid { background: #fff; border-color: #ddd; }
  .markdown-body h1, .markdown-body h2 { border-color: #ddd; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .preview__wrap { scroll-behavior: auto; }
}

.render-error {
  color: var(--danger);
  padding: 20px 22px;
  border: 1px solid var(--danger);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--danger) 6%, transparent);
  display: grid;
  gap: 8px;
}
.render-error strong { font-size: 14px; }
.render-error code {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--text);
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 10px 12px;
}

.katex-error {
  color: var(--danger);
  background: color-mix(in srgb, var(--danger) 10%, transparent);
  border-bottom: 1px dotted var(--danger);
  padding: 0 3px;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.92em;
}

.btn:disabled,
.btn[aria-disabled='true'],
.btn.is-disabled,
button:disabled.btn,
button:disabled.segmented__item,
button:disabled.focus-dock__btn,
button:disabled.lightbox__btn,
button:disabled.dropdown__item,
button:disabled.sidebar__icon-btn,
button:disabled.toc__close,
button:disabled.file__action,
button:disabled.project__action,
button:disabled.tab__close,
button:disabled.find-bar__btn,
button:disabled.find-bar__toggle {
  opacity: 0.5;
  filter: grayscale(0.2);
  cursor: not-allowed;
  pointer-events: none;
  transform: none !important;
  box-shadow: none !important;
}
.btn--primary:disabled,
.btn--primary.is-disabled,
.btn--primary[aria-disabled='true'] {
  background: var(--bg-elev-3);
  color: var(--text-muted);
  border-color: var(--border);
}
.btn--primary:disabled::after,
.btn--primary.is-disabled::after,
.btn--primary[aria-disabled='true']::after { display: none; }

.preview.is-reading .code-copy,
.preview.is-reading .code-lang,
.preview.is-reading .diagram-expand { display: none; }
.preview.is-reading pre:hover .code-copy,
.preview.is-reading pre:focus-within .code-copy { display: inline-flex; opacity: 0.6; }

.file--empty {
  color: var(--text-dim);
  cursor: default;
  font-style: italic;
}

.toast.has-action {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding-right: 10px;
  /* Toasts default to pointer-events:none so they don't block the app.
     When the toast has an action (e.g. Undo), the button must receive clicks. */
  pointer-events: auto;
}
.toast__label { display: inline-block; }
.toast__action {
  background: color-mix(in srgb, var(--accent) 24%, transparent);
  color: var(--text);
  border: 1px solid color-mix(in srgb, var(--accent) 55%, transparent);
  border-radius: 6px;
  padding: 4px 10px;
  font-size: 11.5px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out), transform var(--t-fast) var(--ease-out);
}
.toast__action:hover { background: color-mix(in srgb, var(--accent) 40%, transparent); border-color: var(--accent); transform: translateY(-1px); }
.toast__action:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 2px; }

/* Find & replace. Fixed top-right under the tabs row. A left chevron
   sits next to stacked find + replace rows; replace animates via
   max-height/opacity + margin so the chevron and row move together.
   See the media queries at the bottom for tablet/mobile. */
.find-bar {
  position: fixed;
  top: calc(var(--topbar-h) + 42px); /* 34px tabs + 8px gap */
  right: 16px;
  width: 400px;
  max-width: calc(100vw - 32px);
  background: color-mix(in srgb, var(--bg-elev-2) 96%, transparent);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  border: 1px solid var(--border-strong);
  align-items: flex-start; /* chevron tracks the find-row top, not the
                              midpoint of the expanded find+replace stack */
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  display: none;
  gap: 4px;
  padding: 5px;
  z-index: 90;
}
.find-bar.is-open { display: flex; }
/* Chevron rotates 90° when replace expands (VS Code / DevTools convention). */
.find-bar__expand {
  flex-shrink: 0;
  width: 20px;
  min-height: 28px;
  padding: 0;
  display: inline-grid;
  place-items: center;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 5px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out);
}
.find-bar__expand svg { transition: transform 220ms var(--ease-out); }
.find-bar__expand:hover { color: var(--text); background: var(--bg-elev-3); }
.find-bar__expand:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 1px; }
.find-bar.is-replace .find-bar__expand svg { transform: rotate(90deg); }
.find-bar.is-replace .find-bar__expand { color: var(--text); }
.find-bar__rows {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  flex-direction: column;
  /* No gap — the replace row animates its own margin-top so spacing
     slides in/out with the row. */
}
.find-bar__row {
  display: flex;
  align-items: center;
  gap: 3px;
  min-width: 0;
}
/* Replace row stays in flow and collapses via max-height + opacity + margin.
   JS sets `inert` to keep collapsed inputs off the tab order. */
.find-bar__row--replace {
  max-height: 0;
  margin-top: 0;
  opacity: 0;
  overflow: hidden;
  pointer-events: none;
  transition: max-height 240ms var(--ease-out),
              margin-top 240ms var(--ease-out),
              opacity 180ms var(--ease-out);
}
.find-bar.is-replace .find-bar__row--replace {
  max-height: 200px; /* cap accommodates wrapping replace buttons <360px */
  margin-top: 8px;
  opacity: 1;
  pointer-events: auto;
}
@media (prefers-reduced-motion: reduce) {
  .find-bar__row--replace,
  .find-bar__hint,
  .find-bar__expand svg { transition: none; }
}

/* "Match hidden in preview" hint (mermaid fence, raw HTML, comment, math).
   Same expand/collapse idiom as the replace row. */
.find-bar__hint {
  display: flex;
  align-items: center;
  gap: 8px;
  max-height: 0;
  margin-top: 0;
  opacity: 0;
  overflow: hidden;
  padding: 0 6px;
  font-size: 11px;
  color: color-mix(in srgb, var(--warning) 80%, var(--text));
  transition: max-height 220ms var(--ease-out),
              margin-top 220ms var(--ease-out),
              opacity 160ms var(--ease-out);
}
.find-bar__hint.is-visible {
  max-height: 60px;
  margin-top: 6px;
  opacity: 1;
}
.find-bar__hint svg { flex-shrink: 0; color: var(--warning); }
.find-bar__hint-text { line-height: 1.35; word-break: break-word; }
.find-bar__field {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 5px 8px;
  background: var(--bg-elev-3);
  border: 1px solid var(--border);
  border-radius: 5px;
  transition: border-color var(--t-fast) var(--ease-out), box-shadow var(--t-fast) var(--ease-out);
}
.find-bar__field:focus-within {
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  box-shadow: 0 0 0 2px var(--accent-ring);
}
.find-bar__field svg { color: var(--text-muted); flex-shrink: 0; }
.find-bar__input {
  flex: 1 1 auto;
  background: transparent;
  border: 0;
  color: var(--text);
  font-size: 13px;
  min-width: 0;
  outline: none;
}
.find-bar__input.is-no-match { color: var(--danger); }
.find-bar__input.is-invalid { color: var(--warning); }
.find-bar__count {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-muted);
  flex-shrink: 0;
  min-width: 36px;
  text-align: right;
}
/* Search-option toggles (Aa / W / .*). Container kept unstyled — a
   border+bg here would read as a second detached "field". */
.find-bar__toggles {
  display: inline-flex;
  gap: 2px;
  flex-shrink: 0;
}
.find-bar__toggle {
  width: 26px;
  height: 28px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 5px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out);
}
.find-bar__toggle:hover {
  color: var(--text);
  background: var(--bg-elev-3);
  border-color: var(--border);
}
.find-bar__toggle.is-active {
  background: color-mix(in srgb, var(--accent) 26%, transparent);
  color: var(--text);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 40%, transparent) inset;
}
.find-bar__toggle:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 1px; }
/* Hairline divider between toggles and nav controls. Hidden when the
   row wraps (≤900px). */
.find-bar__row > .find-bar__controls::before {
  content: '';
  width: 1px;
  height: 16px;
  background: var(--border);
  margin: 0 3px 0 1px;
  align-self: center;
  flex-shrink: 0;
}
.find-bar__controls { display: inline-flex; gap: 1px; flex-shrink: 0; }
.find-bar__btn {
  width: 28px;
  height: 28px;
  display: inline-grid;
  place-items: center;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 5px;
  cursor: pointer;
  transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
}
.find-bar__btn:hover {
  color: var(--text);
  background: var(--bg-elev-3);
  border-color: var(--border);
}
.find-bar__btn:focus-visible { outline: 2px solid var(--accent-ring); outline-offset: 1px; }
.find-bar__btn--text {
  width: auto;
  padding: 0 10px;
  font-size: 12px;
  font-weight: 500;
}
.find-bar__close { margin-left: 2px; }

/* Find bar responsive:
   Desktop (>900px): 400px dialog, top-right below the tabs.
   Tablet  (≤900px): fluid, row wraps when cramped.
   Mobile  (≤560px): field on its own line. */

@media (max-width: 900px) {
  .find-bar {
    left: 14px;
    right: 14px;
    top: calc(var(--topbar-h) + 46px); /* 40px tabs + 6px gap */
    width: auto;
    max-width: none;
  }
  .find-bar__row {
    flex-wrap: wrap;
    row-gap: 5px;
  }
  /* Min-basis keeps the field readable; below it, toggles + controls wrap. */
  .find-bar__field { flex: 1 1 200px; }
  /* Wrapped: push controls to the far right of line 2. */
  .find-bar__row > .find-bar__controls { margin-left: auto; }
  .find-bar__row > .find-bar__controls::before { display: none; }
}

@media (max-width: 560px) {
  .find-bar {
    top: calc(var(--topbar-h) + 44px); /* 40px tabs (mobile.css) + 4px gap */
    left: 8px;
    right: 8px;
    border-radius: 8px;
  }
  .find-bar__field { flex: 1 1 100%; }
  .find-bar__expand { width: 18px; }
}

/* Find-match highlights in the rendered preview. Overrides the UA
   yellow/black defaults; scroll positioning is handled in JS. */
mark.find-match {
  background: color-mix(in srgb, var(--warning) 38%, transparent);
  color: inherit;
  border-radius: 2px;
  padding: 0 1px;
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--warning) 50%, transparent);
}
mark.find-match--active {
  background: var(--accent);
  color: #041611;
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 75%, transparent);
  animation: find-pulse 420ms var(--ease-out, ease-out) 1;
}
/* Light theme accent is darker; white reads better on it than dark text. */
:root[data-theme='light'] mark.find-match--active { color: #ffffff; }
@keyframes find-pulse {
  0%   { filter: brightness(1.6);
         box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 60%, transparent); }
  100% { filter: brightness(1);
         box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 75%, transparent); }
}
@media (prefers-reduced-motion: reduce) {
  mark.find-match--active { animation: none; }
}