/* ==========================================================================
   The Mom Test - Warm Book Stylesheet
   Typography: Georgia, serif | 20px body | 1.7 line height
   Layout: Collapsible Sidebar Table of Contents + Centered Reading Column
   ========================================================================== */

:root {
  --bg-color: #f7f1e3;
  --sidebar-bg: #efe7d3;
  --card-bg: #fffcf4;
  --text-color: #242424;
  --text-muted: #6b6357;
  --accent: #9d3f11;
  --accent-hover: #7b2f0a;
  --accent-bg: rgba(157, 63, 17, 0.08);
  --border: #dfd4be;
  --border-subtle: #eae0cd;
  --callout-bg: #faeed4;
  --callout-border: #d48b20;
  --nav-bg: rgba(247, 241, 227, 0.94);
  --active-chapter-bg: rgba(157, 63, 17, 0.12);
  --kbd-bg: #e6dcbe;
  --shadow: rgba(45, 30, 10, 0.08);
}

* {
  box-sizing: border-box;
}

.no-transitions,
.no-transitions * {
  transition: none !important;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: Georgia, serif;
  font-size: 20px;
  line-height: 1.7;
  background-color: var(--bg-color);
  color: var(--text-color);
  overflow-x: hidden;
}

/* ==========================================================================
   Overall Layout (Sidebar + Main)
   ========================================================================== */

.book-layout {
  display: flex;
  min-height: 100vh;
  min-height: 100dvh;
  position: relative;
}

/* ==========================================================================
   Sidebar Navigation (Desktop collapsible + Mobile drawer)
   ========================================================================== */

.book-sidebar {
  width: 320px;
  min-width: 320px;
  background-color: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  height: 100vh;
  position: sticky;
  top: 0;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  z-index: 50;
}

/* Desktop collapse behavior */
@media (min-width: 960px) {
  .book-sidebar {
    transition: margin-left 0.25s cubic-bezier(0.4, 0, 0.2, 1),
                visibility 0.25s ease;
  }

  html.sidebar-collapsed .book-sidebar {
    margin-left: -320px;
    visibility: hidden;
    pointer-events: none;
  }
}

.sidebar-header {
  padding: 1.5rem 1.25rem 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-book-title {
  display: block;
  font-family: Georgia, serif;
  font-size: 1.15rem;
  font-weight: bold;
  line-height: 1.35;
  color: var(--text-color);
  text-decoration: none;
}

.sidebar-book-title:hover {
  color: var(--accent);
}

.sidebar-book-author {
  font-family: Georgia, serif;
  font-size: 0.85rem;
  font-style: italic;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.sidebar-toc {
  padding: 1rem 1.25rem 2rem 1.25rem;
  flex: 1;
}

.sidebar-toc-heading {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: bold;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.sidebar-toc ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sidebar-toc > ul > li {
  margin: 0.4rem 0;
}

.sidebar-toc ul ul {
  padding-left: 1rem;
  margin-top: 0.25rem;
  border-left: 1px solid var(--border);
}

.sidebar-toc ul ul li {
  margin: 0.2rem 0;
}

.sidebar-toc a {
  display: block;
  font-family: Georgia, serif;
  font-size: 0.88rem;
  line-height: 1.4;
  color: var(--text-color);
  text-decoration: none;
  padding: 0.35rem 0.5rem;
  border-radius: 4px;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.sidebar-toc a:hover {
  color: var(--accent);
  background-color: var(--accent-bg);
}

.sidebar-toc a.active-chapter {
  color: var(--accent);
  background-color: var(--active-chapter-bg);
  font-weight: bold;
  box-shadow: inset 3px 0 0 var(--accent);
}

/* ==========================================================================
   Main Content Area
   ========================================================================== */

.book-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   Top Utility Bar
   ========================================================================== */

.book-top-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--nav-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0.6rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-family: Georgia, serif;
  font-size: 0.9rem;
}

.top-bar-left,
.top-bar-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.sidebar-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text-color);
  font-family: Georgia, serif;
  font-size: 0.88rem;
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  box-shadow: 0 1px 2px var(--shadow);
  transition: all 0.15s ease;
}

.sidebar-toggle-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.toggle-icon {
  font-size: 1.1rem;
  line-height: 1;
}

.book-top-bar a {
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.book-top-bar a:hover {
  color: var(--accent);
  background-color: var(--accent-bg);
}

/* ==========================================================================
   Reading Content
   ========================================================================== */

.reading-container {
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  padding: 40px 24px 80px 24px;
}

p {
  text-align: justify;
  margin: 1.25rem 0;
}

h1, h2, h3 {
  font-family: Georgia, serif;
  color: var(--text-color);
}

h1 {
  font-size: 2rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.5rem;
  margin-top: 2.25rem;
  margin-bottom: 0.75rem;
  color: var(--accent);
}

h3 {
  font-size: 1.25rem;
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1.75rem auto;
  border-radius: 4px;
}

/* ==========================================================================
   Index Hero Page
   ========================================================================== */

.index-hero {
  text-align: center;
  padding: 4rem 1rem 3rem 1rem;
}

.hero-title {
  font-size: 2.4rem;
  line-height: 1.25;
  margin-bottom: 1rem;
}

.hero-author {
  font-size: 1.2rem;
  font-style: italic;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
}

.start-reading-btn {
  display: inline-block;
  background-color: var(--accent);
  color: #ffffff !important;
  font-family: Georgia, serif;
  font-size: 1.15rem;
  padding: 0.85rem 2rem;
  border-radius: 8px;
  text-decoration: none !important;
  box-shadow: 0 4px 12px var(--shadow);
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.start-reading-btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
}

/* ==========================================================================
   Callout & Dialogue
   ========================================================================== */

.rule-of-thumb {
  background-color: var(--callout-bg);
  border-left: 4px solid var(--callout-border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  margin: 1.75rem 0;
}

.rule-of-thumb p {
  margin: 0;
}

.rule-of-thumb em {
  font-weight: bold;
  font-style: normal;
  color: var(--accent);
}

.dialogue {
  border-left: 2px solid var(--border);
  padding-left: 1rem;
  margin: 0.4rem 0;
}

.dialogue p {
  margin: 0;
}

.dialogue .speaker,
span.s1, span.s2, span.s3 {
  font-weight: bold;
  color: var(--accent);
  margin-right: 0.25rem;
}

.dialogue em {
  color: var(--text-muted);
}

/* ==========================================================================
   Bottom Navigation
   ========================================================================== */

.bottom-chapter-nav {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.bottom-nav-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.nav-card {
  display: flex;
  flex-direction: column;
  padding: 0.85rem 1.1rem;
  background-color: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-color);
  font-family: Georgia, serif;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.nav-card:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 12px var(--shadow);
  text-decoration: none;
}

.nav-card.prev-card {
  text-align: left;
}

.nav-card.next-card {
  text-align: right;
}

.card-direction {
  font-size: 0.78rem;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.card-title {
  font-size: 0.95rem;
  font-weight: bold;
}

.nav-card.empty-card {
  visibility: hidden;
  pointer-events: none;
}

/* ==========================================================================
   Mobile & Tablet Drawer (< 960px)
   ========================================================================== */

@media (max-width: 959px) {
  .book-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 1000;
    width: min(320px, 88vw);
    min-width: 0;
    height: 100%;
    height: 100dvh;
    margin-left: 0 !important;
    visibility: visible !important;
    transform: translateX(-100%);
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.25);
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
  }

  .book-sidebar.drawer-animating,
  .book-sidebar.open {
    transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  }

  .book-sidebar.open {
    transform: translateX(0);
  }

  .sidebar-backdrop {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 999;
  }

  .sidebar-backdrop.open {
    display: block;
  }

  body.drawer-open {
    overflow: hidden;
  }

  .reading-container {
    padding: 30px 16px 60px 16px;
  }

  p {
    text-align: left;
  }

  .bottom-nav-grid {
    grid-template-columns: 1fr;
  }

  .nav-card.next-card {
    text-align: left;
  }
}