/* ===== Design System: Kids Finance Comics ===== */

:root {
  /* Primary - warm orange */
  --color-primary: #FF8C42;
  --color-primary-light: #FFB87A;
  --color-primary-dark: #E06B1F;

  /* Book accent colors */
  --color-t00: #4ECDC4;
  --color-t01: #FF6B9D;
  --color-t03: #7C5CFC;
  --color-t04: #FFD93D;

  /* Backgrounds */
  --color-bg: #FFF8F0;
  --color-bg-page: #FFFFFF;
  --color-bg-warm: #FFF0E0;

  /* Text */
  --color-text: #2D2D2D;
  --color-text-secondary: #6B6B6B;
  --color-text-light: #999999;

  /* Borders */
  --color-border: #F0E6D8;
  --color-border-light: #F8F0E8;

  /* Knowledge card colors */
  --color-tip-bg: #E8F5E9;
  --color-tip-border: #66BB6A;
  --color-warning-bg: #FFF3E0;
  --color-warning-border: #FFA726;
  --color-activity-bg: #E3F2FD;
  --color-activity-border: #42A5F5;
  --color-dialogue-bg: #F3E5F5;
  --color-dialogue-border: #AB47BC;

  /* Spacing */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-card: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-book: 0 8px 32px rgba(0,0,0,0.12);
  --shadow-hover: 0 12px 40px rgba(0,0,0,0.16);

  /* Typography */
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-display: "Comic Sans MS", "PingFang SC", cursive;

  /* Sizes */
  --font-xs: 12px;
  --font-sm: 14px;
  --font-base: 18px;
  --font-lg: 22px;
  --font-xl: 28px;
  --font-2xl: 36px;
  --font-3xl: 48px;
  --font-4xl: 64px;

  /* Layout */
  --max-width: 1200px;
  --header-height: 64px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-base);
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

a {
  color: var(--color-primary-dark);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-primary);
}

img, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,248,240,0.95);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--color-border);
  height: var(--header-height);
  display: flex;
  align-items: center;
  padding: 0 24px;
}

.site-header .logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--color-primary-dark);
}

.site-header .logo-icon {
  font-size: 28px;
}

.site-header nav {
  margin-left: auto;
  display: flex;
  gap: 24px;
}

.site-header nav a {
  font-size: var(--font-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  transition: all 0.2s;
}

.site-header nav a:hover,
.site-header nav a.active {
  color: var(--color-primary-dark);
  background: var(--color-bg-warm);
}

/* ===== Footer ===== */
.site-footer {
  background: var(--color-bg-warm);
  border-top: 2px solid var(--color-border);
  padding: 40px 24px;
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--font-sm);
  line-height: 2;
}

.site-footer .disclaimer {
  max-width: 600px;
  margin: 0 auto 16px;
  font-size: var(--font-xs);
  color: var(--color-text-light);
}

/* ===== Container ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Hero Section ===== */
.hero {
  min-height: calc(100vh - var(--header-height));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 24px;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #FFF8F0 0%, #FFE8D0 50%, #FFF0E0 100%);
  z-index: -1;
}

.hero-illustration {
  width: 320px;
  height: 320px;
  margin-bottom: 32px;
}

.hero h1 {
  font-size: var(--font-3xl);
  font-weight: 800;
  color: var(--color-primary-dark);
  margin-bottom: 16px;
  line-height: 1.3;
}

.hero .subtitle {
  font-size: var(--font-lg);
  color: var(--color-text-secondary);
  margin-bottom: 40px;
  max-width: 500px;
}

.hero .cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 16px 40px;
  background: var(--color-primary);
  color: white;
  font-size: var(--font-lg);
  font-weight: 700;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  transition: all 0.3s;
  box-shadow: 0 4px 16px rgba(255,140,66,0.4);
  text-decoration: none;
}

.hero .cta-btn:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255,140,66,0.5);
  color: white;
}

/* ===== Features Section ===== */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  padding: 60px 24px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.feature-card {
  background: var(--color-bg-page);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  transition: all 0.3s;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
  border-color: var(--color-primary-light);
}

.feature-card .icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-text);
}

.feature-card p {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ===== Bookshelf ===== */
.bookshelf-section {
  padding: 60px 24px 80px;
}

.bookshelf-section h2 {
  text-align: center;
  font-size: var(--font-2xl);
  font-weight: 800;
  color: var(--color-primary-dark);
  margin-bottom: 48px;
}

.bookshelf-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 32px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.book-card {
  background: var(--color-bg-page);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: all 0.3s;
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  display: block;
}

.book-card:hover {
  transform: translateY(-6px) rotate(1deg);
  box-shadow: var(--shadow-hover);
}

.book-card .cover {
  height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.book-card .cover svg,
.book-card .cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.book-card .age-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(255,255,255,0.95);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: var(--font-xs);
  font-weight: 700;
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-sm);
}

.book-card .info {
  padding: 20px;
}

.book-card .info h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 4px;
}

.book-card .info .subtitle {
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  margin-bottom: 12px;
}

.book-card .info .meta {
  display: flex;
  gap: 12px;
  font-size: var(--font-xs);
  color: var(--color-text-light);
}

.book-card .info .meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ===== Reader ===== */
.reader-container {
  display: flex;
  min-height: calc(100vh - var(--header-height));
}

/* Sidebar */
.reader-sidebar {
  width: 260px;
  background: var(--color-bg-page);
  border-right: 2px solid var(--color-border);
  padding: 24px 0;
  overflow-y: auto;
  flex-shrink: 0;
  position: sticky;
  top: var(--header-height);
  height: calc(100vh - var(--header-height));
}

.reader-sidebar .book-title {
  padding: 0 20px 16px;
  font-size: var(--font-base);
  font-weight: 700;
  color: var(--color-primary-dark);
  border-bottom: 2px solid var(--color-border);
  margin-bottom: 8px;
}

.reader-sidebar .chapter-list {
  list-style: none;
}

.reader-sidebar .chapter-item {
  display: block;
  padding: 12px 20px;
  font-size: var(--font-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  border-left: 3px solid transparent;
}

.reader-sidebar .chapter-item:hover {
  background: var(--color-bg-warm);
  color: var(--color-text);
}

.reader-sidebar .chapter-item.active {
  background: var(--color-bg-warm);
  color: var(--color-primary-dark);
  font-weight: 600;
  border-left-color: var(--color-primary);
}

.reader-sidebar .chapter-item .chapter-num {
  font-size: var(--font-xs);
  color: var(--color-text-light);
  display: block;
  margin-bottom: 2px;
}

/* Main reading area */
.reader-main {
  flex: 1;
  padding: 40px;
  max-width: 800px;
  margin: 0 auto;
}

.reader-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--color-border);
}

.reader-controls .mode-toggle {
  display: flex;
  gap: 4px;
  background: var(--color-bg-warm);
  padding: 4px;
  border-radius: var(--radius-sm);
}

.reader-controls .mode-btn {
  padding: 6px 14px;
  border: none;
  background: none;
  font-size: var(--font-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
}

.reader-controls .mode-btn.active {
  background: var(--color-bg-page);
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-sm);
}

.reader-controls .font-size-control {
  display: flex;
  align-items: center;
  gap: 8px;
}

.reader-controls .font-btn {
  width: 32px;
  height: 32px;
  border: 2px solid var(--color-border);
  background: var(--color-bg-page);
  border-radius: 50%;
  font-size: var(--font-sm);
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.reader-controls .font-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* Page types */
.page {
  margin-bottom: 48px;
}

.page-chapter-title {
  text-align: center;
  padding: 60px 20px;
  background: linear-gradient(135deg, var(--color-bg-warm) 0%, var(--color-bg) 100%);
  border-radius: var(--radius-xl);
  border: 3px solid var(--color-border);
  margin-bottom: 48px;
}

.page-chapter-title .chapter-num {
  font-family: var(--font-display);
  font-size: var(--font-xl);
  color: var(--color-primary);
  margin-bottom: 8px;
}

.page-chapter-title h2 {
  font-size: var(--font-2xl);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 8px;
}

.page-chapter-title .chapter-subtitle {
  font-size: var(--font-base);
  color: var(--color-text-secondary);
}

.page-chapter-title .illustration {
  max-width: 300px;
  margin: 24px auto 0;
}

/* Comic panel */
.page-comic-panel {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  background: var(--color-bg-page);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.page-comic-panel.reverse {
  flex-direction: row-reverse;
}

.page-comic-panel .panel-illustration {
  flex: 0 0 45%;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-bg-warm);
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-comic-panel .panel-content {
  flex: 1;
}

.page-comic-panel .panel-content h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--color-text);
}

.page-comic-panel .panel-content p {
  font-size: var(--font-base);
  line-height: 1.8;
  color: var(--color-text);
}

/* Speech bubble */
.speech-bubble {
  position: relative;
  background: var(--color-bg-page);
  border: 2px solid var(--color-border);
  border-radius: 20px;
  padding: 14px 18px;
  margin: 16px 0;
  font-size: var(--font-sm);
  color: var(--color-text);
  max-width: 80%;
  box-shadow: var(--shadow-sm);
}

.speech-bubble::before {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 24px;
  width: 0;
  height: 0;
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-top: 10px solid var(--color-border);
}

.speech-bubble::after {
  content: '';
  position: absolute;
  bottom: -7px;
  left: 26px;
  width: 0;
  height: 0;
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
  border-top: 8px solid var(--color-bg-page);
}

.speech-bubble .character {
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 4px;
}

/* Knowledge card */
.page-knowledge-card {
  border-radius: var(--radius-lg);
  padding: 24px;
  border-left: 5px solid;
  margin-bottom: 32px;
}

.page-knowledge-card.tip {
  background: var(--color-tip-bg);
  border-left-color: var(--color-tip-border);
}

.page-knowledge-card.warning {
  background: var(--color-warning-bg);
  border-left-color: var(--color-warning-border);
}

.page-knowledge-card.activity {
  background: var(--color-activity-bg);
  border-left-color: var(--color-activity-border);
}

.page-knowledge-card.dialogue {
  background: var(--color-dialogue-bg);
  border-left-color: var(--color-dialogue-border);
}

.page-knowledge-card .card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.page-knowledge-card .card-icon {
  font-size: 24px;
}

.page-knowledge-card .card-title {
  font-size: var(--font-lg);
  font-weight: 700;
}

.page-knowledge-card .card-body {
  font-size: var(--font-base);
  line-height: 1.8;
}

.page-knowledge-card .card-body ul,
.page-knowledge-card .card-body ol {
  padding-left: 20px;
  margin-top: 8px;
}

.page-knowledge-card .card-body li {
  margin-bottom: 6px;
}

/* Activity page */
.page-activity {
  background: var(--color-activity-bg);
  border: 3px dashed var(--color-activity-border);
  border-radius: var(--radius-xl);
  padding: 32px;
}

.page-activity h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-activity-border);
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-activity .steps {
  list-style: none;
  counter-reset: step;
}

.page-activity .steps li {
  counter-increment: step;
  padding: 12px 0 12px 48px;
  position: relative;
  font-size: var(--font-base);
  border-bottom: 1px dashed var(--color-activity-border);
}

.page-activity .steps li:last-child {
  border-bottom: none;
}

.page-activity .steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 10px;
  width: 32px;
  height: 32px;
  background: var(--color-activity-border);
  color: white;
  font-weight: 700;
  font-size: var(--font-sm);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Dialogue page */
.page-dialogue {
  background: var(--color-dialogue-bg);
  border: 3px solid var(--color-dialogue-border);
  border-radius: var(--radius-xl);
  padding: 32px;
}

.page-dialogue h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-dialogue-border);
}

.dialogue-line {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  align-items: flex-start;
}

.dialogue-line .avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
  background: var(--color-bg-page);
  border: 2px solid var(--color-dialogue-border);
}

.dialogue-line .dialogue-text {
  background: var(--color-bg-page);
  border-radius: 16px;
  padding: 12px 16px;
  font-size: var(--font-base);
  line-height: 1.7;
  box-shadow: var(--shadow-sm);
}

/* Data viz */
.page-data-viz {
  background: var(--color-bg-page);
  border: 3px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 32px;
  text-align: center;
}

.page-data-viz h3 {
  font-size: var(--font-lg);
  font-weight: 700;
  margin-bottom: 20px;
}

.page-data-viz .data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: var(--font-sm);
}

.page-data-viz .data-table th {
  background: var(--color-primary);
  color: white;
  padding: 12px 16px;
  font-weight: 600;
  text-align: left;
}

.page-data-viz .data-table th:first-child {
  border-radius: var(--radius-sm) 0 0 0;
}

.page-data-viz .data-table th:last-child {
  border-radius: 0 var(--radius-sm) 0 0;
}

.page-data-viz .data-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

.page-data-viz .data-table tr:nth-child(even) {
  background: var(--color-bg);
}

/* Page navigation */
.page-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 32px 0;
  border-top: 2px solid var(--color-border);
  margin-top: 48px;
}

.page-nav .nav-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  background: var(--color-bg-page);
  border: 2px solid var(--color-border);
  border-radius: 50px;
  font-size: var(--font-sm);
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.page-nav .nav-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
  box-shadow: var(--shadow-sm);
}

.page-nav .nav-btn:disabled,
.page-nav .nav-btn.disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.page-nav .page-indicator {
  font-size: var(--font-sm);
  color: var(--color-text-light);
}

/* ===== About Page ===== */
.about-hero {
  text-align: center;
  padding: 60px 24px 40px;
  background: linear-gradient(135deg, var(--color-bg-warm) 0%, var(--color-bg) 100%);
}

.about-hero h1 {
  font-size: var(--font-2xl);
  font-weight: 800;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
}

.about-hero p {
  font-size: var(--font-lg);
  color: var(--color-text-secondary);
  max-width: 500px;
  margin: 0 auto;
}

.about-section {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px;
}

.about-section h2 {
  font-size: var(--font-xl);
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-text);
  padding-bottom: 12px;
  border-bottom: 3px solid var(--color-primary-light);
}

.about-section p {
  margin-bottom: 16px;
  line-height: 1.8;
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.team-member {
  text-align: center;
  padding: 20px;
  background: var(--color-bg-page);
  border-radius: var(--radius-md);
  border: 2px solid var(--color-border);
}

.team-member .emoji {
  font-size: 40px;
  margin-bottom: 8px;
}

.team-member .name {
  font-weight: 700;
  font-size: var(--font-sm);
}

.team-member .role {
  font-size: var(--font-xs);
  color: var(--color-text-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root {
    --font-base: 16px;
    --font-lg: 18px;
    --font-xl: 24px;
    --font-2xl: 30px;
    --font-3xl: 36px;
  }

  .site-header {
    padding: 0 16px;
  }

  .site-header nav {
    gap: 8px;
  }

  .site-header nav a {
    padding: 6px 10px;
    font-size: var(--font-xs);
  }

  .hero-illustration {
    width: 200px;
    height: 200px;
  }

  .features {
    grid-template-columns: 1fr;
    padding: 40px 16px;
  }

  .bookshelf-grid {
    grid-template-columns: 1fr;
  }

  .reader-container {
    flex-direction: column;
  }

  .reader-sidebar {
    width: 100%;
    height: auto;
    position: relative;
    top: 0;
    border-right: none;
    border-bottom: 2px solid var(--color-border);
    max-height: 200px;
  }

  .reader-main {
    padding: 24px 16px;
  }

  .page-comic-panel {
    flex-direction: column !important;
  }

  .page-comic-panel .panel-illustration {
    flex: none;
    width: 100%;
  }

  .page-nav .nav-btn {
    padding: 10px 16px;
    font-size: var(--font-xs);
  }

  .team-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .site-header .logo span {
    display: none;
  }

  .page-activity .steps li {
    padding-left: 40px;
  }
}