/* ============================================
   CINQ ANS — Book reading experience
   Mobile-first responsive design
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #faf9f6;
  --bg-secondary: #f0efeb;
  --text: #2d2d2d;
  --text-secondary: #6b6b6b;
  --accent: #c0392b;
  --accent-light: #e74c3c;
  --border: #e0ddd8;
  --sidebar-bg: #f5f4f0;
  --sidebar-text: #4a4a4a;
  --sidebar-active: #c0392b;
  --cover-bg: #0d0d0d;
  --cover-text: #f0f0f0;
  --blockquote-bg: #f5f3ef;
  --table-header-bg: #f0efeb;
  --table-border: #ddd8d0;
  --shadow: rgba(0, 0, 0, 0.08);
  --code-bg: #f0efeb;
  --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --content-width: 700px;
  --sidebar-width: 280px;
  --topbar-height: 50px;
  --transition: 0.3s ease;
}

[data-theme="dark"] {
  --bg: #1a1a1a;
  --bg-secondary: #242424;
  --text: #e0e0e0;
  --text-secondary: #999;
  --accent: #e05545;
  --accent-light: #f06050;
  --border: #333;
  --sidebar-bg: #141414;
  --sidebar-text: #bbb;
  --sidebar-active: #e05545;
  --cover-bg: #0a0a0a;
  --cover-text: #f0f0f0;
  --blockquote-bg: #222;
  --table-header-bg: #252525;
  --table-border: #3a3a3a;
  --shadow: rgba(0, 0, 0, 0.3);
  --code-bg: #252525;
}

/* ============================================
   MOBILE BASE (default styles)
   ============================================ */

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-serif);
  background: var(--bg);
  color: var(--text);
  line-height: 1.78;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* --- Progress Bar --- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--accent);
  z-index: 1001;
  width: 0;
  transition: width 0.15s ease-out;
}

/* --- Top Bar (mobile: always visible) --- */
.top-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--topbar-height);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  z-index: 999;
  transition: background var(--transition), border-color var(--transition);
}

.top-bar-home {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px;
  margin-left: 4px;
  transition: color 0.15s;
  -webkit-tap-highlight-color: transparent;
}

.top-bar-home:hover {
  color: var(--accent);
}

.top-bar-title {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 60%;
  text-align: center;
}

/* --- Menu Toggle (hamburger) — visible on mobile by default --- */
.menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  margin-left: -10px;
  -webkit-tap-highlight-color: transparent;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  transition: all 0.3s ease;
  border-radius: 1px;
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Theme Toggle --- */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: 10px;
  margin-right: -10px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  transition: color 0.2s;
  -webkit-tap-highlight-color: transparent;
}

.theme-toggle:hover {
  color: var(--text);
}

.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* --- Sidebar (mobile: hidden off-screen by default) --- */
.sidebar {
  position: fixed;
  top: var(--topbar-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  max-width: 85vw;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: 1.2rem 0;
  z-index: 998;
  transform: translateX(-100%);
  transition: background var(--transition), border-color var(--transition), transform 0.3s ease;
}

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

.sidebar-header {
  padding: 0 1.5rem 1rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.6rem;
}

.sidebar-title {
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.15rem;
}

.sidebar-subtitle {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  flex-direction: column;
}

.nav-link {
  display: block;
  padding: 0.6rem 1.5rem;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--sidebar-text);
  text-decoration: none;
  transition: all 0.15s ease;
  line-height: 1.4;
  border-left: 3px solid transparent;
  -webkit-tap-highlight-color: transparent;
}

.nav-link:hover {
  color: var(--text);
  background: var(--bg);
}

.nav-link.active {
  color: var(--sidebar-active);
  font-weight: 600;
  border-left-color: var(--sidebar-active);
  background: var(--bg);
}

.nav-num {
  display: inline-block;
  width: 1.5em;
  color: var(--accent);
  font-weight: 700;
}

/* --- Sidebar Overlay (mobile) --- */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 997;
}

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

/* --- Main Content (mobile: full width) --- */
.content {
  margin-left: 0;
  padding-top: var(--topbar-height);
  min-height: 100vh;
}

/* --- Chapters (mobile) --- */
.chapter {
  display: none;
  padding: 1.5rem 1.2rem 5rem;
  max-width: 100%;
  margin: 0 auto;
  animation: fadeIn 0.4s ease;
}

.chapter.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Cover (mobile) --- */
.cover {
  max-width: 100%;
  padding: 0;
  margin: 0;
  background: var(--cover-bg);
  min-height: calc(100vh - var(--topbar-height));
  min-height: calc(100dvh - var(--topbar-height));
  display: none;
  align-items: center;
  justify-content: center;
}

.cover.active {
  display: flex;
}

.cover-content {
  text-align: center;
  padding: 2rem 1.5rem;
  max-width: 600px;
}

.cover-top-line {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: #888;
  margin-bottom: 2rem;
}

.cover-title {
  font-family: var(--font-sans);
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: 0.06em;
  color: var(--cover-text);
  line-height: 1;
  margin-bottom: 1rem;
}

.cover-subtitle {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: #ccc;
  line-height: 1.5;
  margin-bottom: 1.8rem;
  font-style: italic;
}

.cover-separator {
  width: 50px;
  height: 3px;
  background: var(--accent);
  margin: 0 auto 1.8rem;
}

.cover-author {
  font-family: var(--font-sans);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--accent);
  margin-bottom: 0.8rem;
}

.cover-description {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: #888;
  line-height: 1.6;
  margin-bottom: 2.5rem;
}

.start-reading {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--cover-text);
  background: transparent;
  border: 2px solid var(--accent);
  padding: 0.85rem 2rem;
  cursor: pointer;
  letter-spacing: 0.05em;
  transition: all 0.25s ease;
  -webkit-tap-highlight-color: transparent;
}

.start-reading:hover,
.start-reading:active {
  background: var(--accent);
  color: #fff;
}

/* --- Chapter Header (mobile) --- */
.chapter-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.chapter-label {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 0.5rem;
}

.chapter-title {
  font-family: var(--font-sans);
  font-size: 1.8rem;
  font-weight: 800;
  line-height: 1.15;
  color: var(--text);
  letter-spacing: -0.01em;
}

/* --- Typography (mobile) --- */
.chapter-body h2 {
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  margin: 2.2rem 0 0.8rem;
  line-height: 1.25;
}

.chapter-body h3 {
  font-family: var(--font-sans);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  margin: 1.8rem 0 0.6rem;
  line-height: 1.3;
}

.chapter-body p {
  margin-bottom: 1.1rem;
  text-align: left;
}

.chapter-body p:last-child {
  margin-bottom: 0;
}

.chapter-body strong {
  font-weight: 700;
  color: var(--text);
}

.chapter-body em {
  font-style: italic;
}

.chapter-body a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: color 0.15s;
}

.chapter-body a:hover {
  color: var(--accent-light);
}

/* --- Horizontal Rule --- */
.chapter-body hr {
  border: none;
  height: 1px;
  background: var(--border);
  margin: 2rem auto;
  max-width: 100px;
}

/* --- Blockquotes (mobile) --- */
.chapter-body blockquote {
  border-left: 3px solid var(--accent);
  background: var(--blockquote-bg);
  padding: 1rem 1rem;
  margin: 1.5rem -0.3rem;
  border-radius: 0 6px 6px 0;
  transition: background var(--transition);
}

.chapter-body blockquote p {
  font-size: 0.92rem;
  margin-bottom: 0.7rem;
  text-align: left;
}

.chapter-body blockquote p:last-child {
  margin-bottom: 0;
}

.chapter-body blockquote strong {
  color: var(--accent);
}

/* --- Tables (mobile: scroll horizontally) --- */
.table-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 1.5rem -0.3rem;
  border-radius: 0;
  border: 1px solid var(--table-border);
}

.chapter-body table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.82rem;
  line-height: 1.5;
  min-width: 400px;
}

.chapter-body thead {
  background: var(--table-header-bg);
}

.chapter-body th {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.78rem;
  text-align: left;
  padding: 0.65rem 0.8rem;
  border-bottom: 2px solid var(--table-border);
  white-space: nowrap;
}

.chapter-body td {
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--table-border);
}

.chapter-body tr:last-child td {
  border-bottom: none;
}

.chapter-body tbody tr:hover {
  background: var(--blockquote-bg);
}

/* --- Lists --- */
.chapter-body ul, .chapter-body ol {
  margin: 0.8rem 0 1.1rem 1.3rem;
}

.chapter-body li {
  margin-bottom: 0.35rem;
  padding-left: 0.2rem;
}

.chapter-body li::marker {
  color: var(--accent);
}

/* --- Code --- */
.chapter-body code {
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.85em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

/* --- Chapter Navigation (mobile: full width bottom bar) --- */
.chapter-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0.8rem;
  background: var(--bg);
  border-top: 1px solid var(--border);
  z-index: 100;
  transition: background var(--transition), border-color var(--transition);
}

.nav-btn {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.6rem 0.8rem;
  transition: color 0.15s;
  -webkit-tap-highlight-color: transparent;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.nav-btn:hover,
.nav-btn:active {
  color: var(--accent);
}

.nav-btn:disabled {
  opacity: 0.3;
  cursor: default;
}

.nav-btn:disabled:hover {
  color: var(--text-secondary);
}

.nav-chapter-label {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
}

/* --- Share Bar --- */
.share-bar {
  margin-top: 3rem;
  padding: 1.5rem 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  flex-wrap: wrap;
  font-family: var(--font-sans);
}

.share-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 600;
  letter-spacing: 0.03em;
}

.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s;
  -webkit-tap-highlight-color: transparent;
}

.share-btn:hover {
  color: var(--text);
  border-color: var(--accent);
}

.share-btn.share-linkedin:hover {
  color: #0a66c2;
  border-color: #0a66c2;
}

.share-btn.copied {
  color: var(--accent);
  border-color: var(--accent);
}

/* --- Footer --- */
.book-footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  text-align: center;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.book-footer hr {
  max-width: 160px;
  margin: 0 auto 1.2rem;
}

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

.book-footer a:hover {
  text-decoration: underline;
}

/* --- Swipe hint (mobile only) --- */
.swipe-hint {
  display: block;
  text-align: center;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  color: var(--text-secondary);
  padding: 0.5rem;
  opacity: 0.6;
}

/* ============================================
   TABLET (min-width: 641px)
   ============================================ */
@media (min-width: 641px) {
  html {
    font-size: 17px;
  }

  .top-bar {
    padding: 0 1.2rem;
  }

  .chapter {
    padding: 2.5rem 2rem 6rem;
    max-width: calc(var(--content-width) + 4rem);
  }

  .chapter-header {
    margin-bottom: 2.5rem;
    padding-bottom: 1.8rem;
  }

  .chapter-title {
    font-size: 2.2rem;
  }

  .chapter-body h2 {
    font-size: 1.35rem;
    margin-top: 2.5rem;
  }

  .chapter-body h3 {
    font-size: 1.12rem;
    margin-top: 2rem;
  }

  .chapter-body p {
    margin-bottom: 1.2rem;
    text-align: justify;
    hyphens: auto;
    -webkit-hyphens: auto;
  }

  .chapter-body blockquote {
    padding: 1.2rem 1.4rem;
    margin: 1.8rem 0;
  }

  .table-wrapper {
    margin: 1.8rem 0;
    border-radius: 6px;
  }

  .chapter-body table {
    font-size: 0.86rem;
    min-width: unset;
  }

  .chapter-body th {
    padding: 0.75rem 1rem;
    font-size: 0.82rem;
  }

  .chapter-body td {
    padding: 0.65rem 1rem;
  }

  .cover-title {
    font-size: clamp(3.5rem, 10vw, 5rem);
  }

  .cover-subtitle {
    font-size: 1.25rem;
  }

  .cover-author {
    font-size: 1.3rem;
  }

  .cover-description {
    font-size: 0.82rem;
  }

  .chapter-nav {
    padding: 0.6rem 1.2rem;
  }

  .nav-btn {
    font-size: 0.82rem;
    padding: 0.5rem 1rem;
  }

  .book-footer {
    margin-top: 4rem;
    padding-top: 2rem;
    font-size: 0.78rem;
  }

  .swipe-hint {
    display: none;
  }
}

/* ============================================
   DESKTOP (min-width: 1025px)
   ============================================ */
@media (min-width: 1025px) {
  html {
    font-size: 18px;
  }

  .top-bar {
    padding: 0 1.5rem;
    height: 56px;
  }

  .top-bar-title {
    font-size: 0.85rem;
    max-width: none;
  }

  /* Sidebar: always visible on desktop */
  .sidebar {
    transform: translateX(0);
    max-width: var(--sidebar-width);
  }

  .sidebar-overlay {
    display: none !important;
  }

  /* Hide hamburger on desktop */
  .menu-toggle {
    display: none;
  }

  /* Content: offset by sidebar */
  .content {
    margin-left: var(--sidebar-width);
  }

  /* Chapters: more breathing room */
  .chapter {
    padding: 3rem 1.5rem 6rem;
    max-width: calc(var(--content-width) + 3rem);
  }

  .chapter-header {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
  }

  .chapter-title {
    font-size: 2.6rem;
  }

  .chapter-body h2 {
    font-size: 1.45rem;
    margin-top: 2.8rem;
    margin-bottom: 1rem;
  }

  .chapter-body h3 {
    font-size: 1.15rem;
    margin-top: 2.2rem;
    margin-bottom: 0.8rem;
  }

  .chapter-body blockquote {
    padding: 1.2rem 1.5rem;
  }

  /* Chapter nav: offset by sidebar */
  .chapter-nav {
    left: var(--sidebar-width);
    padding: 0.8rem 1.5rem;
  }
}

/* Fix: CSS custom property in media query doesn't work as expected,
   use JS or set topbar-height as a fixed value for desktop */
@media (min-width: 1025px) {
  .top-bar {
    height: 56px;
  }
  .sidebar {
    top: 56px;
  }
  .content {
    padding-top: 56px;
  }
}

/* --- Print --- */
@media print {
  .top-bar, .sidebar, .sidebar-overlay, .chapter-nav, .progress-bar,
  .start-reading, .cover-top-line, .menu-toggle, .theme-toggle, .swipe-hint {
    display: none !important;
  }

  .content {
    margin-left: 0;
    padding-top: 0;
  }

  .chapter {
    display: block !important;
    page-break-before: always;
    padding: 2rem 0;
    max-width: 100%;
  }

  .cover {
    background: #fff;
    color: #000;
    min-height: auto;
    page-break-after: always;
  }

  .cover-title, .cover-subtitle, .cover-author, .cover-description {
    color: #000;
  }

  body {
    background: #fff;
    color: #000;
    font-size: 11pt;
    line-height: 1.6;
  }

  .chapter-body blockquote {
    background: #f5f5f5;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}

/* --- Scrollbar (Webkit) --- */
.sidebar::-webkit-scrollbar {
  width: 4px;
}

.sidebar::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

/* --- Selection --- */
::selection {
  background: rgba(192, 57, 43, 0.15);
  color: var(--text);
}

/* --- Touch improvements --- */
@media (hover: none) and (pointer: coarse) {
  .nav-link {
    padding: 0.7rem 1.5rem;
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .start-reading {
    padding: 1rem 2.5rem;
    font-size: 0.9rem;
  }
}