/* ========================================
   BookBub — Theme System & Styles
   ======================================== */

/* ---------- CSS Custom Properties ---------- */

:root,
[data-theme="light"] {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-code: #f1f3f5;
  --text-primary: #1a1a2e;
  --text-secondary: #6c757d;
  --text-link: var(--accent);
  --border: #dee2e6;
  --border-light: #e9ecef;
  --accent: #4a6fa5;
  --accent-hover: #3a5a85;
  --accent-glow: rgba(74, 111, 165, 0.12);
  --font-body: 'Lora', Georgia, 'Times New Roman', serif;
  --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-code: 'Source Code Pro', 'Fira Code', 'Cascadia Code', monospace;
  --max-width: 680px;
  --header-height: 56px;
}

[data-theme="dark"] {
  --bg-primary: #1a1a2e;
  --bg-secondary: #16213e;
  --bg-code: #1e1e3a;
  --text-primary: #e8e8f0;
  --text-secondary: #a0a0b8;
  --text-link: var(--accent);
  --border: #2a2a4a;
  --border-light: #222244;
  --accent: #7ba0d4;
  --accent-hover: #9bb8e8;
  --accent-glow: rgba(123, 160, 212, 0.15);
}

[data-theme="sepia"] {
  --bg-primary: #f4ecd8;
  --bg-secondary: #ece5ce;
  --bg-code: #e8dfc4;
  --text-primary: #433422;
  --text-secondary: #7a6a54;
  --text-link: var(--accent);
  --border: #d4c9b0;
  --border-light: #ddd5bf;
  --accent: #8b6b4a;
  --accent-hover: #a07d58;
  --accent-glow: rgba(139, 107, 74, 0.15);
}

/* Accent color variants */
[data-accent="blue"]   { --accent: #4a6fa5; --accent-hover: #3a5a85; --accent-glow: rgba(74,111,165,0.12); }
[data-accent="teal"]   { --accent: #2d8f8f; --accent-hover: #247373; --accent-glow: rgba(45,143,143,0.12); }
[data-accent="warm"]   { --accent: #b87333; --accent-hover: #9e632b; --accent-glow: rgba(184,115,51,0.12); }
[data-accent="forest"] { --accent: #4a7c59; --accent-hover: #3d6b4b; --accent-glow: rgba(74,124,89,0.12); }

[data-theme="dark"][data-accent="blue"]   { --accent: #7ba0d4; --accent-hover: #9bb8e8; --accent-glow: rgba(123,160,212,0.15); }
[data-theme="dark"][data-accent="teal"]   { --accent: #5bb8b8; --accent-hover: #7dcfcf; --accent-glow: rgba(91,184,184,0.15); }
[data-theme="dark"][data-accent="warm"]   { --accent: #d49a5a; --accent-hover: #e0b07a; --accent-glow: rgba(212,154,90,0.15); }
[data-theme="dark"][data-accent="forest"] { --accent: #6ba37a; --accent-hover: #85ba93; --accent-glow: rgba(107,163,122,0.15); }

[data-theme="sepia"][data-accent="blue"]   { --accent: #6b8fa5; --accent-hover: #5a7a8c; --accent-glow: rgba(107,143,165,0.15); }
[data-theme="sepia"][data-accent="teal"]   { --accent: #5a8f8f; --accent-hover: #4a7a7a; --accent-glow: rgba(90,143,143,0.15); }
[data-theme="sepia"][data-accent="warm"]   { --accent: #8b6b4a; --accent-hover: #a07d58; --accent-glow: rgba(139,107,74,0.15); }
[data-theme="sepia"][data-accent="forest"] { --accent: #6b8a5a; --accent-hover: #5a7a4a; --accent-glow: rgba(107,138,90,0.15); }

/* ---------- Reset & Base ---------- */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 18px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background: var(--bg-primary);
  line-height: 1.7;
  transition: background 0.3s ease, color 0.3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--text-link);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover { color: var(--accent-hover); }

/* Focus-visible for keyboard users */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ---------- Site Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 1.25rem;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg-primary) 82%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.site-logo {
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  white-space: nowrap;
}
.site-logo:hover { color: var(--accent); }

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.375rem;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.nav-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--accent);
}

/* Theme icon visibility */
[data-theme="light"] .icon-dark,
[data-theme="light"] .icon-sepia,
[data-theme="dark"] .icon-light,
[data-theme="dark"] .icon-sepia,
[data-theme="sepia"] .icon-light,
[data-theme="sepia"] .icon-dark {
  display: none;
}

/* ---------- Table of Contents (Library) ---------- */

.toc {
  max-width: var(--max-width);
  margin: 3rem auto 6rem;
  padding: 0 1.5rem;
}

.toc-heading {
  font-family: var(--font-ui);
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 2.5rem;
  color: var(--text-primary);
}

.toc-collection {
  margin-bottom: 2.5rem;
}

.toc-collection-title {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-light);
}

.toc-writings {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.toc-writing {
  padding: 0;
}

.toc-writing-link {
  font-family: var(--font-ui);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  display: block;
  line-height: 1.35;
}

.toc-writing-link:hover {
  color: var(--accent);
}

.toc-writing-excerpt {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  line-height: 1.5;
}

.toc-writing-date,
.toc-writing-words {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: inline;
}

.toc-writing-date::after {
  content: " · ";
}

.toc-empty {
  color: var(--text-secondary);
  font-style: italic;
}

/* Series expandable sections */
.toc-series { border: none; margin-bottom: 0.5rem; }

.toc-series-title {
  font-family: var(--font-ui);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  padding: 0.25rem 0;
  user-select: none;
}

.toc-series-parts {
  margin-top: 0.5rem;
  padding-left: 1rem;
  border-left: 2px solid var(--border-light);
}

.toc-series-part {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.toc-series-part .toc-writing-link {
  font-size: 0.9rem;
  font-weight: 400;
}

.toc-part-number {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--text-secondary);
  min-width: 3.5rem;
}

.toc-part-label {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ---------- Reading Page ---------- */

.reading-page {
  max-width: var(--max-width);
  margin: 2rem auto 6rem;
  padding: 0 1.5rem;
}

.writing-header {
  margin-bottom: 2.5rem;
  text-align: center;
}

.writing-context {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--accent);
  display: inline-block;
  margin-bottom: 0.5rem;
}

.writing-series-badge {
  font-family: var(--font-ui);
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 0.75rem;
}

.writing-title {
  font-family: var(--font-ui);
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.writing-meta {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.writing-body {
  font-size: 1rem;
  line-height: 1.8;
}

.writing-body p {
  margin-bottom: 1.25rem;
}

.writing-body h2,
.writing-body h3 {
  font-family: var(--font-ui);
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}
.writing-body h2 { font-size: 1.3rem; }
.writing-body h3 { font-size: 1.1rem; }

/* Standard blockquote */
.writing-body blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

/* Pull quotes */
.writing-body .pull-quote {
  border-left: none;
  padding: 1.5rem 2rem;
  margin: 2rem 0;
  text-align: center;
  font-style: normal;
  background: var(--bg-secondary);
  border-radius: 8px;
}

.writing-body .pull-quote::before {
  content: "“";
  display: block;
  font-size: 3rem;
  line-height: 1;
  color: var(--accent);
  opacity: 0.4;
  margin-bottom: -0.25rem;
}

.pull-quote-text {
  font-family: var(--font-body);
  font-size: 1.15rem;
  line-height: 1.6;
  color: var(--text-primary);
}

.pull-quote-attribution {
  display: block;
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-style: normal;
  font-family: var(--font-ui);
}

/* Scene breaks */
.scene-break {
  text-align: center;
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin: 2.25rem 0;
  line-height: 1;
  user-select: none;
  opacity: 0.6;
  letter-spacing: 0.5em;
}

/* Dialogue blocks */
.dialogue {
  margin: 0.75rem 0;
  padding-left: 1.5rem;
  border-left: 2px solid var(--accent);
  display: flex;
  gap: 0.5rem;
}

.dialogue-speaker {
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent);
  white-space: nowrap;
  min-width: fit-content;
}

.dialogue-text {
  font-size: 0.95rem;
  color: var(--text-primary);
}

/* Code */
.writing-body code {
  font-family: var(--font-code);
  font-size: 0.85rem;
  background: var(--bg-code);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  word-break: break-word;
}

.writing-body pre {
  background: var(--bg-code);
  padding: 1rem 1.25rem;
  border-radius: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 1.5rem 0;
  font-size: 0.85rem;
  line-height: 1.6;
}

.writing-body pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  word-break: normal;
}

/* Images */
.writing-body img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  margin: 1.5rem 0;
  display: block;
}

/* Lists */
.writing-body ul,
.writing-body ol {
  margin: 1rem 0;
  padding-left: 1.5rem;
}
.writing-body li { margin-bottom: 0.25rem; }

/* Tables */
.writing-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-family: var(--font-ui);
  font-size: 0.85rem;
}
.writing-body th,
.writing-body td {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  text-align: left;
}
.writing-body th {
  background: var(--bg-secondary);
  font-weight: 600;
}

/* Series navigation */
.series-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-light);
}

.series-nav-link {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--text-secondary);
  max-width: 50%;
  line-height: 1.4;
}
.series-nav-link:hover { color: var(--accent); }
.series-nav-next { text-align: right; margin-left: auto; }
.series-nav-prev { text-align: left; }
.series-nav:only-child { justify-content: flex-end; }

/* Writing footer */
.writing-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-light);
  text-align: center;
}

.back-to-library {
  font-family: var(--font-ui);
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.back-to-library:hover { color: var(--accent); }

/* ---------- TOC Drawer ---------- */

.toc-drawer {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: min(340px, 85vw);
  height: calc(100vh - var(--header-height));
  background: var(--bg-primary);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  z-index: 200;
  padding: 1rem 0;
  box-shadow: 4px 0 24px rgba(0,0,0,0.06);
}

.toc-drawer[hidden] { display: none; }

.toc-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem 0.75rem;
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 0.5rem;
}

.toc-drawer-header h2 {
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
}

.toc-drawer-content {
  padding: 0 0.5rem;
  font-size: 0.9rem;
}

.toc-drawer-content .toc-empty {
  padding: 1rem;
  text-align: center;
}

/* Drawer groups */
.toc-drawer-group {
  margin-bottom: 0.25rem;
}

.toc-drawer-group-title {
  font-family: var(--font-ui);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  padding: 0.75rem 0.75rem 0.25rem;
}

.toc-drawer-list {
  list-style: none;
  padding: 0;
}

.toc-drawer-list li { margin: 0; }

.toc-drawer-link {
  display: block;
  padding: 0.4rem 0.75rem;
  border-radius: 4px;
  font-family: var(--font-ui);
  font-size: 0.85rem;
  color: var(--text-primary);
  transition: background 0.1s, color 0.1s;
  line-height: 1.35;
}

.toc-drawer-link:hover {
  background: var(--bg-secondary);
  color: var(--accent);
}

.toc-drawer-link--active {
  color: var(--accent);
  background: var(--accent-glow);
  font-weight: 600;
}

/* ---------- Reading Progress Indicator ---------- */

.reading-progress-bar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent);
  z-index: 99;
  transition: width 0.3s ease;
  opacity: 0.7;
}

.reading-progress-bar.hidden { display: none; }

/* Scroll restore banner */
.scroll-restore-banner {
  text-align: center;
  padding: 0.5rem 0;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--accent);
  cursor: pointer;
  border-bottom: 1px solid var(--border-light);
  background: var(--bg-secondary);
  transition: background 0.15s;
  user-select: none;
}

.scroll-restore-banner:hover {
  background: var(--accent-glow);
}

/* ---------- Loading / Skeleton ---------- */

.toc-drawer-skeleton {
  padding: 0.75rem;
}

.skeleton-line {
  height: 0.75rem;
  background: var(--border-light);
  border-radius: 4px;
  margin-bottom: 0.5rem;
  animation: skeleton-pulse 1.5s ease-in-out infinite;
}

.skeleton-line:nth-child(1) { width: 60%; }
.skeleton-line:nth-child(2) { width: 85%; }
.skeleton-line:nth-child(3) { width: 45%; }
.skeleton-line:nth-child(4) { width: 75%; }
.skeleton-line:nth-child(5) { width: 55%; }

@keyframes skeleton-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* ---------- Responsive ---------- */

@media (max-width: 640px) {
  html { font-size: 16px; }
  .writing-title { font-size: 1.5rem; }
  .toc { margin-top: 2rem; }
  .reading-page { margin-top: 1.5rem; }
  .site-header { padding: 0 0.75rem; }

  .pull-quote-text { font-size: 1rem; }
  .writing-body .pull-quote { padding: 1.25rem 1rem; }

  .series-nav { flex-direction: column; align-items: center; gap: 0.5rem; }
  .series-nav-link { max-width: 100%; text-align: center; }
  .series-nav-next { margin-left: 0; }

  .toc-drawer { width: 85vw; }
}

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

/* ---------- Print ---------- */

@media print {
  .site-header,
  .toc-drawer,
  .reading-progress-bar,
  .scroll-restore-banner,
  .nav-btn,
  .writing-footer { display: none !important; }

  .reading-page { max-width: 100%; margin: 0; padding: 0; }
  .writing-title { font-size: 1.5rem; }
  body { font-size: 11pt; color: #000; background: #fff; }
  a { color: #000; text-decoration: underline; }
  .writing-body a { word-break: break-all; }
}