/* ═══════════════════════════════════════════════════════════════
   course-ui.css — reusable accessibility & reading library
   -----------------------------------------------------------------
   Provides theme tokens (Light / Sepia / Dark) plus styles for:
     • Aa popover (text size / font / theme)
     • Focus mode toggle
     • Reading progress line + bottom reading-position bar
     • Search (inline input + results dropdown)
     • Vocabulary terms + global term popover
     • Skip link + visible focus ring
     • Reduced-motion + print

   Consuming sites use these CSS variables for their own content
   styles; never hardcode theme-sensitive colours in site CSS.

   Load ORDER matters (course-ui.css before site styles.css) so that
   sites can override variables if they want site-specific theming.
   ═══════════════════════════════════════════════════════════════ */

/* ── Theme tokens — Light (default) ────────────────────────── */
:root {
  /* font system */
  --cu-font-scale:   1;
  --cu-body-font:    -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Helvetica, Arial, sans-serif;
  --cu-heading-font: var(--cu-body-font);

  /* brand accent (may be overridden by site) */
  --cu-accent:       #F2B13E;

  /* surfaces */
  --cu-bg-page:      #ffffff;
  --cu-bg-surface:   #f8f9fb;
  --cu-bg-elevated:  #ffffff;

  /* text */
  --cu-text:         #1d1d1f;
  --cu-text-body:    #374151;
  --cu-text-muted:   #4a5568;
  --cu-text-strong:  #1a1a2e;

  /* borders */
  --cu-border-soft:  #f0f0f5;
  --cu-border:       #e5e7eb;
  --cu-border-strong:#d1d5db;

  /* content components */
  --cu-callout-bg:   linear-gradient(135deg, rgba(90,198,210,0.08), rgba(31,69,127,0.06));
  --cu-callout-border:rgba(90,198,210,0.25);
  --cu-callout-title:#1a8a95;
  --cu-blockquote-bg:rgba(242,177,62,0.06);
  --cu-blockquote-border:var(--cu-accent);

  /* IM / data tables */
  --cu-table-header-bg:   #c8c8c8;
  --cu-table-header-text: #4a4a4a;
  --cu-table-th-bg:       #f5f5f5;
  --cu-table-th-text:     #6b6b6b;
  --cu-table-td-text:     #6b7280;
  --cu-table-td-alt:      #fafafa;
  --cu-table-td-first:    #5a5a5a;
  --cu-table-divider:     #f0f0f0;

  /* solution / expandable panel */
  --cu-solution-bg:    #f3f4f6;
  --cu-solution-border:#e5e7eb;

  /* inline code */
  --cu-code-inline-bg:   #f1f5f9;
  --cu-code-inline-text: #1F457F;

  /* completion button */
  --cu-complete-idle-border:#d1d5db;
  --cu-complete-idle-text:  #6b7280;

  /* reading progress */
  --cu-reading-track: rgba(31,69,127,0.12);
  --cu-reading-fill:  var(--cu-accent);
  --cu-reading-pos-bg:#ffffff;
  --cu-reading-pos-border:#e5e7eb;
  --cu-reading-pos-text:#6b7280;
  --cu-reading-pos-strong:#1a1a2e;

  /* vocabulary popover */
  --cu-term-bg:       rgba(90,198,210,0.12);
  --cu-term-border:   rgba(90,198,210,0.55);
  --cu-popover-bg:    #1a1d24;
  --cu-popover-text:  #f3f4f6;

  /* toolbar hook (sites set these to match their own topbar) */
  --cu-tb-btn-bg:     rgba(255,255,255,0.12);
  --cu-tb-btn-border: rgba(255,255,255,0.22);
  --cu-tb-btn-text:   #ffffff;
}

/* ── Sepia theme ───────────────────────────────────────────── */
[data-theme="sepia"] {
  --cu-bg-page:      #f5edd6;
  --cu-bg-surface:   #ede4cb;
  --cu-bg-elevated:  #f0e6c8;
  --cu-text:         #3e2f1c;
  --cu-text-body:    #4a3a22;
  --cu-text-muted:   #6b5b45;
  --cu-text-strong:  #2e2210;
  --cu-border-soft:  #e3d6ae;
  --cu-border:       #d4c6a8;
  --cu-border-strong:#b8a983;
  --cu-callout-bg:   #ede4cb;
  --cu-callout-border:#b8a983;
  --cu-callout-title:#6b5b2a;
  --cu-blockquote-bg:#ece2c4;
  --cu-blockquote-border:#b8940a;
  --cu-table-header-bg:   #d4c6a8;
  --cu-table-header-text: #3e2f1c;
  --cu-table-th-bg:       #e3d6ae;
  --cu-table-th-text:     #4a3a22;
  --cu-table-td-text:     #4a3a22;
  --cu-table-td-alt:      #ece2c4;
  --cu-table-td-first:    #3e2f1c;
  --cu-table-divider:     #d4c6a8;
  --cu-solution-bg:    #ece2c4;
  --cu-solution-border:#d4c6a8;
  --cu-code-inline-bg:   #e3d6ae;
  --cu-code-inline-text: #5a3e1b;
  --cu-complete-idle-border:#b8a983;
  --cu-complete-idle-text:  #6b5b45;
  --cu-reading-track: rgba(62,47,28,0.15);
  --cu-reading-fill:  #b8940a;
  --cu-reading-pos-bg:#ede4cb;
  --cu-reading-pos-border:#d4c6a8;
  --cu-reading-pos-text:#6b5b45;
  --cu-reading-pos-strong:#3e2f1c;
  --cu-term-bg:       rgba(107,91,69,0.18);
  --cu-term-border:   #8a7350;
  --cu-popover-bg:    #3e2f1c;
  --cu-popover-text:  #f5edd6;
}

/* ── Dark theme ────────────────────────────────────────────── */
[data-theme="dark"] {
  --cu-bg-page:      #111317;
  --cu-bg-surface:   #191c22;
  --cu-bg-elevated:  #1a1d24;
  --cu-text:         #e6e6ee;
  --cu-text-body:    #c5c9d3;
  --cu-text-muted:   #9aa0aa;
  --cu-text-strong:  #ffffff;
  --cu-border-soft:  #242832;
  --cu-border:       #2a2f38;
  --cu-border-strong:#3a3f4a;
  --cu-callout-bg:   rgba(90,198,210,0.06);
  --cu-callout-border:rgba(90,198,210,0.22);
  --cu-callout-title:#6ed3de;
  --cu-blockquote-bg:rgba(242,177,62,0.08);
  --cu-blockquote-border:var(--cu-accent);
  --cu-table-header-bg:   #2a2f38;
  --cu-table-header-text: #c5c9d3;
  --cu-table-th-bg:       #1f232b;
  --cu-table-th-text:     #9aa0aa;
  --cu-table-td-text:     #c5c9d3;
  --cu-table-td-alt:      #1c1f27;
  --cu-table-td-first:    #e6e6ee;
  --cu-table-divider:     #242832;
  --cu-solution-bg:    #1a1d24;
  --cu-solution-border:#2a2f38;
  --cu-code-inline-bg:   #242832;
  --cu-code-inline-text: #8ab4ea;
  --cu-complete-idle-border:#3a3f4a;
  --cu-complete-idle-text:  #9aa0aa;
  --cu-reading-track: rgba(255,255,255,0.08);
  --cu-reading-fill:  var(--cu-accent);
  --cu-reading-pos-bg:#15181e;
  --cu-reading-pos-border:#2a2f38;
  --cu-reading-pos-text:#9aa0aa;
  --cu-reading-pos-strong:#e6e6ee;
  --cu-term-bg:       rgba(90,198,210,0.18);
  --cu-term-border:   rgba(90,198,210,0.55);
  --cu-popover-bg:    #2a3a4a;
  --cu-popover-text:  #f3f4f6;
}

/* ═══════════════════════════════════════════════════════════════
   FONT SCALE + BODY FONT (applied at :root / <html>)
   Sites should NOT override font-size on html; use --cu-font-scale.
   ═══════════════════════════════════════════════════════════════ */
html.cu-root {
  font-size: calc(16px * var(--cu-font-scale, 1));
  scroll-padding-top: 76px;
}
body.cu-body {
  font-family: var(--cu-body-font);
  background: var(--cu-bg-page);
  color: var(--cu-text);
  transition: background 0.25s, color 0.25s;
}

/* ═══════════════════════════════════════════════════════════════
   OPENDYSLEXIC FONT (CDN — falls back gracefully if offline)
   ═══════════════════════════════════════════════════════════════ */
@font-face {
  font-family: 'OpenDyslexic';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/npm/open-dyslexic@1.0.3/woff/OpenDyslexic-Regular.woff') format('woff');
}
@font-face {
  font-family: 'OpenDyslexic';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/npm/open-dyslexic@1.0.3/woff/OpenDyslexic-Bold.woff') format('woff');
}
@font-face {
  font-family: 'OpenDyslexic';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url('https://cdn.jsdelivr.net/npm/open-dyslexic@1.0.3/woff/OpenDyslexic-Italic.woff') format('woff');
}

/* ═══════════════════════════════════════════════════════════════
   TOOLBAR CLUSTER — Aa + Focus + Search buttons
   ═══════════════════════════════════════════════════════════════ */
.cu-cluster {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  margin-right: 12px;
  flex-wrap: nowrap;
}
.cu-cluster + .topbar-progress,
.cu-cluster + .overall-progress { margin-left: 0; }

.cu-btn {
  background: var(--cu-tb-btn-bg);
  border: 1px solid var(--cu-tb-btn-border);
  border-radius: 14px;
  color: var(--cu-tb-btn-text);
  cursor: pointer;
  padding: 6px 12px;
  font-size: 0.78rem;
  font-weight: 500;
  line-height: 1;
  font-family: inherit;
  transition: background 0.15s, border-color 0.15s;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.cu-btn:hover { background: rgba(255,255,255,0.2); }
.cu-btn.cu-active {
  background: var(--cu-accent);
  color: #1a1a2e;
  border-color: var(--cu-accent);
}
.cu-btn svg { width: 14px; height: 14px; }

/* ═══════════════════════════════════════════════════════════════
   Aa POPOVER
   ═══════════════════════════════════════════════════════════════ */
.cu-aa-wrap { position: relative; }
.cu-popover {
  display: none;
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  background: var(--cu-bg-elevated);
  border: 1px solid var(--cu-border);
  border-radius: 14px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.22);
  padding: 18px;
  width: 280px;
  z-index: 2500;
}
.cu-popover.cu-open { display: block; }
.cu-aa-section { margin-bottom: 16px; }
.cu-aa-section:last-child { margin-bottom: 0; }
.cu-aa-label {
  font-size: 0.66rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--cu-text-muted);
  margin-bottom: 8px;
}
.cu-aa-row { display: flex; gap: 6px; }
.cu-aa-row .cu-tb {
  flex: 1;
  justify-content: center;
  font-size: 0.78rem;
  padding: 7px 6px;
}
.cu-aa-size-row { display: flex; align-items: center; gap: 8px; }
.cu-aa-size-row .cu-tb {
  width: 36px;
  height: 36px;
  justify-content: center;
  font-size: 1rem;
  padding: 0;
  flex: none;
}
.cu-aa-size-label {
  flex: 1;
  text-align: center;
  font-size: 0.82rem;
  color: var(--cu-text-muted);
  font-variant-numeric: tabular-nums;
}
/* Popover-button palette (sits on page bg, not toolbar bg) */
.cu-popover .cu-tb {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--cu-bg-surface);
  color: var(--cu-text);
  border: 1px solid var(--cu-border);
  border-radius: 8px;
  cursor: pointer;
  font-family: inherit;
  font-weight: 500;
  line-height: 1;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.cu-popover .cu-tb:hover {
  background: var(--cu-bg-page);
  border-color: var(--cu-text-muted);
}
.cu-popover .cu-tb.cu-active {
  background: #1F457F;
  color: #fff;
  border-color: #1F457F;
}
[data-theme="dark"] .cu-popover .cu-tb.cu-active {
  background: var(--cu-accent);
  color: #1a1a2e;
  border-color: var(--cu-accent);
}
[data-theme="sepia"] .cu-popover .cu-tb.cu-active {
  background: #3e2f1c;
  color: #f5edd6;
  border-color: #3e2f1c;
}
/* Theme swatches */
.cu-themes { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; }
.cu-theme-opt { text-align: center; display: flex; flex-direction: column; gap: 4px; }
.cu-theme-opt span { font-size: 0.68rem; color: var(--cu-text-muted); }
.cu-swatch {
  width: 100%;
  height: 36px;
  border-radius: 8px;
  border: 2px solid var(--cu-border);
  cursor: pointer;
  padding: 0;
  transition: border-color 0.15s;
}
.cu-swatch:hover { border-color: var(--cu-text-muted); }
.cu-swatch.cu-active {
  border-color: #1F457F;
  border-width: 2.5px;
}
[data-theme="dark"] .cu-swatch.cu-active { border-color: var(--cu-accent); }
[data-theme="sepia"] .cu-swatch.cu-active { border-color: #3e2f1c; }
.cu-swatch-light { background: #ffffff; }
.cu-swatch-sepia { background: #f5edd6; }
.cu-swatch-dark  { background: #1a1d24; }

/* ═══════════════════════════════════════════════════════════════
   SEARCH
   ═══════════════════════════════════════════════════════════════ */
.cu-search-wrap { position: relative; display: flex; align-items: center; }
.cu-search-input {
  width: 0;
  opacity: 0;
  border: 1px solid var(--cu-tb-btn-border);
  border-radius: 14px;
  padding: 0;
  font-size: 0.82rem;
  font-family: inherit;
  background: rgba(255,255,255,0.12);
  color: #fff;
  outline: none;
  transition: width 0.25s, opacity 0.2s, padding 0.25s, margin 0.25s;
  margin-left: 0;
}
.cu-search-input::placeholder { color: rgba(255,255,255,0.6); }
.cu-search-input.cu-open {
  width: 240px;
  opacity: 1;
  padding: 6px 12px;
  margin-left: 6px;
}
.cu-search-input:focus { border-color: rgba(255,255,255,0.5); background: rgba(255,255,255,0.18); }
.cu-search-results {
  display: none;
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  background: var(--cu-bg-elevated);
  border: 1px solid var(--cu-border);
  border-radius: 14px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.25);
  width: 420px;
  max-height: 440px;
  overflow-y: auto;
  z-index: 2400;
}
.cu-search-results.cu-open { display: block; }
.cu-search-header {
  padding: 10px 14px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--cu-text-muted);
  border-bottom: 1px solid var(--cu-border);
}
.cu-search-result {
  display: block;
  padding: 11px 14px;
  text-decoration: none;
  color: var(--cu-text);
  border-bottom: 1px solid var(--cu-border-soft);
  cursor: pointer;
  transition: background 0.1s;
}
.cu-search-result:last-child { border-bottom: none; }
.cu-search-result:hover,
.cu-search-result:focus-visible {
  background: var(--cu-bg-surface);
  text-decoration: none;
  outline: none;
}
.cu-search-title {
  font-weight: 600;
  font-size: 0.88rem;
  margin-bottom: 3px;
  color: var(--cu-text-strong);
}
.cu-search-snippet {
  font-size: 0.78rem;
  color: var(--cu-text-muted);
  line-height: 1.45;
}
.cu-search-snippet mark {
  background: rgba(242,177,62,0.4);
  color: inherit;
  border-radius: 2px;
  padding: 0 2px;
}
.cu-search-source {
  display: inline-block;
  font-size: 0.66rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--cu-text-muted);
  margin-left: 6px;
  opacity: 0.7;
}
.cu-search-empty {
  padding: 18px 14px;
  font-size: 0.85rem;
  color: var(--cu-text-muted);
  text-align: center;
}
.cu-search-hit {
  background: rgba(242,177,62,0.35) !important;
  border-radius: 3px;
  scroll-margin-top: 80px;
}

/* ═══════════════════════════════════════════════════════════════
   VOCABULARY TERMS + POPOVER
   ═══════════════════════════════════════════════════════════════ */
.cu-term {
  background: var(--cu-term-bg);
  border-bottom: 1.5px dashed var(--cu-term-border);
  padding: 0.05em 0.3em;
  border-radius: 3px;
  cursor: help;
  font-style: normal;
}
.cu-term:focus-visible {
  outline: 2px solid var(--cu-accent);
  outline-offset: 2px;
}
#cu-term-popover {
  display: none;
  position: fixed;
  z-index: 9999;
  background: var(--cu-popover-bg);
  color: var(--cu-popover-text);
  padding: 0.75rem 1rem;
  border-radius: 10px;
  font-size: 0.82rem;
  line-height: 1.55;
  width: max-content;
  max-width: 340px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.32);
  pointer-events: none;
  font-family: var(--cu-body-font);
}
#cu-term-popover.cu-visible { display: block; }
#cu-term-popover::after {
  content: '';
  position: absolute;
  border: 7px solid transparent;
}
#cu-term-popover.cu-arrow-bottom::after {
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border-top-color: var(--cu-popover-bg);
}
#cu-term-popover.cu-arrow-top::after {
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  border-bottom-color: var(--cu-popover-bg);
}
#cu-term-popover strong { color: var(--cu-accent); }

/* ═══════════════════════════════════════════════════════════════
   READING PROGRESS LINE (under topbar)
   ═══════════════════════════════════════════════════════════════ */
.cu-reading-line {
  position: fixed;
  top: 56px; /* override via --cu-topbar-h if your toolbar is taller */
  top: var(--cu-topbar-h, 56px);
  left: 0;
  right: 0;
  height: 3px;
  background: var(--cu-reading-track);
  z-index: 999;
  pointer-events: none;
}
.cu-reading-line-fill {
  display: block;
  height: 100%;
  width: 0;
  background: var(--cu-reading-fill);
  transition: width 0.12s linear;
}

/* ═══════════════════════════════════════════════════════════════
   READING POSITION BAR (bottom strip)
   ═══════════════════════════════════════════════════════════════ */
.cu-reading-pos {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 34px;
  background: var(--cu-reading-pos-bg);
  border-top: 1px solid var(--cu-reading-pos-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  font-size: 0.74rem;
  color: var(--cu-reading-pos-text);
  z-index: 900;
  font-variant-numeric: tabular-nums;
  font-family: var(--cu-body-font);
}
.cu-rp-label {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.cu-rp-section {
  font-weight: 600;
  color: var(--cu-reading-pos-strong);
}
.cu-rp-counter { color: var(--cu-reading-pos-text); }
.cu-rp-progress {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.cu-rp-bar {
  width: 90px;
  height: 4px;
  background: var(--cu-border);
  border-radius: 2px;
  overflow: hidden;
}
.cu-rp-bar-fill {
  height: 100%;
  width: 0;
  background: var(--cu-reading-fill);
  border-radius: 2px;
  transition: width 0.12s linear;
}
.cu-rp-pct {
  min-width: 32px;
  text-align: right;
}

/* Keep the reading-pos strip from covering short content */
body.cu-body main { padding-bottom: 140px; }

/* ═══════════════════════════════════════════════════════════════
   FOCUS MODE — hides the site sidebar, widens content column
   (site CSS controls how the sidebar is actually selected)
   ═══════════════════════════════════════════════════════════════ */
body.cu-focus-mode .sidebar { display: none !important; }
body.cu-focus-mode main,
body.cu-focus-mode .content {
  margin-left: auto;
  margin-right: auto;
  max-width: 980px;
}

/* ═══════════════════════════════════════════════════════════════
   SKIP LINK + GLOBAL FOCUS RING
   ═══════════════════════════════════════════════════════════════ */
.cu-skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--cu-accent);
  color: #1a1a2e;
  padding: 10px 16px;
  font-weight: 700;
  border-radius: 0 0 10px 10px;
  text-decoration: none;
  z-index: 3000;
}
.cu-skip-link:focus {
  left: 12px;
  top: 8px;
  outline: 2px solid #1a1a2e;
  outline-offset: 2px;
}
body.cu-body :focus-visible {
  outline: 2px solid var(--cu-accent);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ═══════════════════════════════════════════════════════════════
   REDUCED MOTION
   ═══════════════════════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ═══════════════════════════════════════════════════════════════
   PRINT
   ═══════════════════════════════════════════════════════════════ */
@media print {
  .cu-cluster,
  .cu-reading-line,
  .cu-reading-pos,
  .cu-popover,
  .cu-search-results,
  #cu-term-popover,
  .cu-skip-link {
    display: none !important;
  }
  body.cu-body { background: #fff; color: #000; }
}

/* ═══════════════════════════════════════════════════════════════
   MOBILE NAVIGATION — burger menu + drawer
   -----------------------------------------------------------------
   The library provides a mobile burger that opens a slide-out drawer
   containing cloned site navigation elements. Sites configure which
   elements to clone via CourseUI.mobile.drawer.sections.

   Breakpoints used by the library:
     ≤ 900px — show burger, sidebar is expected to be hidden
     ≤ 720px — also hide the topbar nav pills / divider / progress
     ≤ 400px — cluster further compresses
   ═══════════════════════════════════════════════════════════════ */

/* Burger button — hidden by default, revealed on mobile */
.cu-burger {
  display: none;
  background: var(--cu-tb-btn-bg);
  border: 1px solid var(--cu-tb-btn-border);
  border-radius: 12px;
  color: var(--cu-tb-btn-text);
  cursor: pointer;
  padding: 7px 10px;
  font-family: inherit;
  line-height: 1;
  flex-shrink: 0;
  margin-right: 8px;
}
.cu-burger:hover { background: rgba(255,255,255,0.2); }
.cu-burger:focus-visible {
  outline: 2px solid var(--cu-accent);
  outline-offset: 2px;
}
.cu-burger svg {
  width: 20px;
  height: 20px;
  display: block;
}

/* Drawer — slides in from the left */
.cu-drawer {
  position: fixed;
  top: 0;
  left: 0;
  width: min(320px, 88vw);
  height: 100vh;
  height: 100dvh;           /* dynamic viewport height on mobile browsers */
  background: var(--cu-bg-elevated);
  border-right: 1px solid var(--cu-border);
  box-shadow: 0 0 40px rgba(0,0,0,0.22);
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  z-index: 3100;
  overflow-y: auto;
  overscroll-behavior: contain;
  display: flex;
  flex-direction: column;
  font-family: var(--cu-body-font);
}
.cu-drawer.cu-open { transform: translateX(0); }

.cu-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--cu-border);
  background: var(--cu-bg-surface);
  flex-shrink: 0;
}
.cu-drawer-title {
  font-size: 0.94rem;
  font-weight: 700;
  color: var(--cu-text-strong);
  letter-spacing: -0.01em;
}
.cu-drawer-close {
  background: transparent;
  border: none;
  color: var(--cu-text-muted);
  cursor: pointer;
  font-size: 1.6rem;
  line-height: 1;
  padding: 2px 10px;
  border-radius: 6px;
}
.cu-drawer-close:hover {
  color: var(--cu-text-strong);
  background: var(--cu-bg-page);
}

.cu-drawer-body {
  flex: 1;
  padding: 14px 0;
  overflow-y: auto;
}
.cu-drawer-section {
  padding: 0 12px 16px;
  border-bottom: 1px solid var(--cu-border-soft);
  margin-bottom: 14px;
}
.cu-drawer-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
}
.cu-drawer-section-title {
  font-size: 0.66rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--cu-text-muted);
  margin: 4px 12px 10px;
}

/* ── Drawer body: neutralise cloned site navigation styles ───
   The drawer clones site navigation into .cu-drawer-body. We reset
   the clone's positioning/background/width so it renders cleanly
   regardless of what the site has done to .sidebar on desktop. */
.cu-drawer-body .sidebar,
.cu-drawer-body aside,
.cu-drawer-body nav,
.cu-drawer-body .nav-dropdown {
  position: static;
  width: auto;
  height: auto;
  min-width: 0;
  max-width: none;
  background: transparent;
  color: var(--cu-text);
  padding: 0;
  margin: 0;
  border: none;
  overflow: visible;
  display: block;
  box-shadow: none;
}

.cu-drawer-body a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  color: var(--cu-text);
  background: transparent;
  text-decoration: none;
  border-radius: 8px;
  border-left: none !important;
  font-size: 0.92rem;
  line-height: 1.35;
  margin: 2px 0;
  min-height: 40px;     /* touch target */
}
.cu-drawer-body a:hover {
  background: var(--cu-bg-surface);
  color: var(--cu-text-strong);
  text-decoration: none;
}
.cu-drawer-body a.active,
.cu-drawer-body a.current {
  background: rgba(242, 177, 62, 0.14);
  color: var(--cu-text-strong);
  font-weight: 600;
}

/* Decorative bits cloned from sidebars */
.cu-drawer-body .nav-num,
.cu-drawer-body .dd-num {
  color: var(--cu-text-muted);
  min-width: 22px;
  font-size: 0.76rem;
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
  opacity: 0.7;
}
.cu-drawer-body .nav-badge {
  display: inline-block;
  font-size: 0.6rem;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--cu-bg-surface);
  color: var(--cu-text-muted);
  margin-top: 2px;
}
.cu-drawer-body .nav-done {
  margin-left: auto;
  color: var(--cu-accent);
  font-weight: 700;
}
.cu-drawer-body .sidebar-chapter,
.cu-drawer-body .nav-dropdown-heading {
  padding: 0 14px 6px;
  font-size: 0.64rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--cu-text-muted);
}
.cu-drawer-body .nav-dropdown-sep {
  border: none;
  border-top: 1px solid var(--cu-border-soft);
  margin: 8px 0;
}

/* ── High-specificity overrides for cloned site navigation ──
   The selectors below use .cu-drawer > .cu-drawer-body to beat
   site-level `.sidebar a` / `.nav-dropdown a` rules which are often
   written in dark-on-dark or light-on-light palettes that only work
   against their original background. We force them to use theme
   tokens regardless of their original source styling. */
.cu-drawer .cu-drawer-body a,
.cu-drawer .cu-drawer-body .sidebar a,
.cu-drawer .cu-drawer-body .sidebar nav a,
.cu-drawer .cu-drawer-body .nav-dropdown a {
  color: var(--cu-text);
  background: transparent;
  border-left: none;
}
.cu-drawer .cu-drawer-body a:hover,
.cu-drawer .cu-drawer-body .sidebar a:hover,
.cu-drawer .cu-drawer-body .nav-dropdown a:hover {
  color: var(--cu-text-strong);
  background: var(--cu-bg-surface);
}
.cu-drawer .cu-drawer-body a.active,
.cu-drawer .cu-drawer-body a.current,
.cu-drawer .cu-drawer-body .sidebar a.active,
.cu-drawer .cu-drawer-body .nav-dropdown a.current {
  background: rgba(242, 177, 62, 0.14);
  color: var(--cu-text-strong);
  font-weight: 600;
}
.cu-drawer .cu-drawer-body .nav-num,
.cu-drawer .cu-drawer-body .dd-num,
.cu-drawer .cu-drawer-body a .nav-num,
.cu-drawer .cu-drawer-body a .dd-num {
  color: var(--cu-text-muted);
}
.cu-drawer .cu-drawer-body .dd-check,
.cu-drawer .cu-drawer-body .nav-done {
  color: var(--cu-accent);
}

/* Backdrop */
.cu-drawer-backdrop {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  z-index: 3050;
}
.cu-drawer-backdrop.cu-open {
  opacity: 1;
  pointer-events: auto;
}

/* Prevent body scrolling while the drawer is open */
body.cu-drawer-open {
  overflow: hidden;
}

/* ═══════════════════════════════════════════════════════════════
   MOBILE BREAKPOINTS
   ═══════════════════════════════════════════════════════════════ */

/* ── Tablet / small laptop — show burger, hide the site sidebar ─ */
@media (max-width: 900px) {
  .cu-burger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  /* Focus mode is moot without a sidebar to hide — burger serves the
     same purpose (show/hide navigation). */
  #cu-btn-focus { display: none; }
}

/* ── Mobile — also hide the topbar nav pills and reading-pos text ─ */
@media (max-width: 720px) {
  .cu-popover {
    width: min(300px, calc(100vw - 24px));
    right: -8px;
  }
  .cu-search-input.cu-open {
    width: min(200px, calc(100vw - 200px));
  }
  .cu-search-results {
    width: calc(100vw - 16px);
    right: -8px;
    max-height: 70vh;
  }
  .cu-reading-pos {
    height: 40px;
    padding: 0 12px;
    font-size: 0.7rem;
  }
  .cu-rp-bar { width: 60px; }
  .cu-rp-counter { display: none; }
  .cu-cluster { gap: 6px; margin-right: 8px; }
  .cu-btn { padding: 6px 10px; font-size: 0.74rem; }
  .cu-burger { margin-right: 6px; padding: 7px 9px; }
}

/* ── Very narrow — further compress ─────────────────────────── */
@media (max-width: 400px) {
  .cu-search-results {
    width: calc(100vw - 8px);
    right: -4px;
  }
  .cu-search-input.cu-open {
    width: min(140px, calc(100vw - 180px));
  }
}