/* ==========================================================================
   TREVOR SWISTCHEW DIGITAL COMPENDIUM - SCOTTISH LITERARY SALON DESIGN SYSTEM
   ========================================================================== */

:root {
  /* Default: Dark Theme (Peat & Loch) */
  --bg-page: #121110;
  --bg-surface: #1a1816;
  --bg-surface-elevated: #24211e;
  --bg-surface-glass: rgba(26, 24, 22, 0.85);
  --border-subtle: #2d2925;
  --border-prominent: #3d3731;
  --text-primary: #ece5da;
  --text-secondary: #b8ad9e;
  --text-muted: #82786b;
  --accent-gold: #c5a059;
  --accent-gold-hover: #dbb369;
  --accent-gold-soft: rgba(197, 160, 89, 0.15);
  --accent-thistle: #9d2b45;
  --accent-loch: #38bdf8;
  --quote-bg: rgba(36, 33, 30, 0.6);
  --tooltip-bg: #221f1b;
  --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.35);

  /* Reading Body Font Size Scale */
  --essay-font-size: 1.125rem; /* 18px default */
  --essay-line-height: 1.82;
}

/* 1. Edinburgh Stone (Light Mode) */
html.theme-light {
  --bg-page: #f7f4ed;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #efeae0;
  --bg-surface-glass: rgba(255, 255, 255, 0.88);
  --border-subtle: #e5ded2;
  --border-prominent: #d4cab9;
  --text-primary: #1e1b18;
  --text-secondary: #544c42;
  --text-muted: #867c6f;
  --accent-gold: #9e7930;
  --accent-gold-hover: #836323;
  --accent-gold-soft: rgba(158, 121, 48, 0.12);
  --accent-thistle: #8b263e;
  --accent-loch: #0284c7;
  --quote-bg: rgba(239, 234, 224, 0.65);
  --tooltip-bg: #ffffff;
  --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.08);
}

/* 2. Aged Parchment (Sepia Mode) */
html.theme-sepia {
  --bg-page: #f2e8d5;
  --bg-surface: #faefe0;
  --bg-surface-elevated: #e5d8be;
  --bg-surface-glass: rgba(250, 239, 224, 0.88);
  --border-subtle: #ddcfb6;
  --border-prominent: #cbb998;
  --text-primary: #292017;
  --text-secondary: #574635;
  --text-muted: #88745f;
  --accent-gold: #966c25;
  --accent-gold-hover: #7d571a;
  --accent-gold-soft: rgba(150, 108, 37, 0.14);
  --accent-thistle: #7c2035;
  --accent-loch: #0369a1;
  --quote-bg: rgba(229, 216, 190, 0.6);
  --tooltip-bg: #f5ebd9;
  --shadow-subtle: 0 4px 20px rgba(78, 54, 25, 0.12);
}

/* 3. Global Styles & Typography Hooks */
body {
  background-color: var(--bg-page);
  color: var(--text-primary);
  transition: background-color 0.25s ease, color 0.25s ease;
  font-family: 'Source Serif 4', 'Lora', Georgia, serif;
  -webkit-font-smoothing: antialiased;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-page);
}
::-webkit-scrollbar-thumb {
  background: var(--border-prominent);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent-gold);
}

/* Dynamic Reading Content Styling */
.essay-content {
  font-size: var(--essay-font-size);
  line-height: var(--essay-line-height);
  color: var(--text-primary);
}

.essay-content p {
  margin-bottom: 1.65rem;
}

/* Classical Literary Drop Cap */
.drop-cap::first-letter {
  font-family: 'Playfair Display', 'Cinzel', Georgia, serif;
  float: left;
  font-size: 3.85rem;
  line-height: 0.82;
  font-weight: 700;
  margin-top: 0.18rem;
  margin-right: 0.65rem;
  padding: 0.1rem;
  color: var(--accent-gold);
  text-shadow: 1px 1px 0px rgba(0, 0, 0, 0.2);
}

/* Thematic Pull Quote Callout */
.pull-quote {
  position: relative;
  margin: 2.5rem 0;
  padding: 1.75rem 2rem;
  background-color: var(--quote-bg);
  border-left: 4px solid var(--accent-gold);
  border-radius: 0 0.5rem 0.5rem 0;
  font-family: 'Playfair Display', Georgia, serif;
  font-style: italic;
  font-size: 1.35rem;
  line-height: 1.65;
  color: var(--text-primary);
  box-shadow: var(--shadow-subtle);
}

.pull-quote::before {
  content: '“';
  position: absolute;
  top: -0.8rem;
  left: 1rem;
  font-size: 4rem;
  color: var(--accent-gold);
  opacity: 0.25;
  font-family: serif;
  line-height: 1;
}

/* Numbered Section Divider with Celtic Motif */
.section-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 3.5rem 0 2.5rem 0;
  text-align: center;
}

.section-divider::before,
.section-divider::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid var(--border-prominent);
}

.section-divider span {
  padding: 0 1.25rem;
  font-family: 'Cinzel', serif;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--accent-gold);
  font-size: 0.95rem;
  text-transform: uppercase;
}

/* Reading Progress Bar */
#reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-loch));
  z-index: 9999;
  width: 0%;
  transition: width 0.1s ease-out;
}

/* Interactive Citations & Footnote Tooltips */
.footnote-ref {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.25rem;
  height: 1.25rem;
  padding: 0 0.35rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-gold);
  background: var(--accent-gold-soft);
  border: 1px solid var(--accent-gold);
  border-radius: 9999px;
  vertical-align: super;
  margin-left: 0.2rem;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
}

.footnote-ref:hover,
.footnote-ref:focus {
  background: var(--accent-gold);
  color: var(--bg-page);
  transform: translateY(-2px);
}

/* Footnote Popover Tooltip */
.footnote-tooltip {
  position: absolute;
  z-index: 50;
  max-width: 20rem;
  padding: 0.85rem 1rem;
  background-color: var(--tooltip-bg);
  border: 1px solid var(--accent-gold);
  border-radius: 0.5rem;
  box-shadow: 0 10px 25px -3px rgba(0, 0, 0, 0.45);
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 0.825rem;
  line-height: 1.5;
  color: var(--text-primary);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s;
}

.footnote-tooltip.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* Audio Player Range Slider Styling */
input[type=range].audio-scrubber {
  -webkit-appearance: none;
  background: var(--border-prominent);
  border-radius: 9999px;
  height: 6px;
  cursor: pointer;
}

input[type=range].audio-scrubber::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  background: var(--accent-gold);
  border-radius: 50%;
  box-shadow: 0 0 6px rgba(0,0,0,0.5);
  transition: transform 0.15s ease;
}

input[type=range].audio-scrubber::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}