/* ==========================================================
 *  ExamHack PC Web - Design System v2 (大厂级)
 *  Tokens: Purple Gradient 5B5CEB → 7C3AED (用户偏好)
 *          Neutral: #F7F8FA bg, 圆角16-24px, 玻璃拟态导航
 * ========================================================== */

/* ---------- 1. Design Tokens ---------- */
:root {
  /* Brand - 紫色渐变体系（用户偏好：linear-gradient(135deg,#5B5CEB,#7C3AED) + 紫色阴影） */
  --primary:          #5B5CEB;
  --primary-deep:     #7C3AED;
  --primary-grad:     linear-gradient(135deg, #5B5CEB 0%, #7C3AED 100%);
  --primary-grad-soft:linear-gradient(135deg, rgba(91,92,235,.12) 0%, rgba(124,58,237,.08) 100%);
  --primary-soft:     rgba(91, 92, 235, 0.10);
  --primary-shadow:   0 6px 20px rgba(91, 92, 235, 0.35);
  --primary-shadow-hover: 0 10px 28px rgba(91, 92, 235, 0.45);

  /* Neutral */
  --bg:            #F7F8FA;
  --bg-soft:       #FFFFFF;
  --surface:       #FFFFFF;
  --surface-2:     #F9FAFB;

  --border:        #EEF0F5;
  --border-light:  #F1F3F7;
  --border-hover:  #D8DBE6;

  --text:          #111827;
  --text-sub:      #4B5563;
  --text-muted:    #6B7280;
  --text-disabled: #9CA3AF;

  /* Semantic */
  --success:   #10B981;
  --danger:    #EF4444;
  --warning:   #F59E0B;
  --info:      #3B82F6;

  /* Radius */
  --r-xs: 8px;
  --r-sm: 12px;
  --r-md: 16px;
  --r-lg: 20px;
  --r-xl: 24px;
  --r-full: 999px;

  /* Shadow */
  --shadow-1: 0 2px 8px rgba(17, 24, 39, 0.04);
  --shadow-2: 0 4px 24px rgba(17, 24, 39, 0.06);
  --shadow-3: 0 12px 48px rgba(17, 24, 39, 0.08);
  --shadow:   var(--shadow-2);

  /* Layout */
  --container-w: 1200px;
  --radius-lg:   var(--r-lg);
  --radius-md:   var(--r-md);
}

/* ---------- 2. Reset & Base ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a { color: inherit; text-decoration: none; }
a:hover { color: var(--primary); }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  outline: none;
}
img { max-width: 100%; display: block; }

/* ---------- 3. Utilities ---------- */
.container { max-width: var(--container-w); margin: 0 auto; padding: 0 24px; }
.flex { display: flex; }
.flex-1 { flex: 1; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-16 { gap: 16px; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-sm { font-size: 13px; }
.text-xs { font-size: 12px; }
.text-lg { font-size: 18px; }
.font-bold { font-weight: 700; }
.font-medium { font-weight: 500; }
.text-primary { color: var(--primary); }
.text-muted { color: var(--text-muted); }
.text-sub { color: var(--text-sub); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }

/* ---------- 4. Buttons (大厂规范：紫色渐变主按钮 + 幽灵按钮) ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 6px;
  height: 40px; padding: 0 20px;
  border-radius: var(--r-full);
  font-weight: 500; font-size: 14px;
  transition: all .2s cubic-bezier(.4,0,.2,1);
  white-space: nowrap;
  border: 1px solid transparent;
}
.btn-sm { height: 34px; padding: 0 16px; font-size: 13px; }
.btn-lg { height: 48px; padding: 0 28px; font-size: 15px; }

.btn-primary {
  background: var(--primary-grad);
  color: #fff;
  box-shadow: var(--primary-shadow);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--primary-shadow-hover);
  color: #fff;
}
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled {
  opacity: .55; cursor: not-allowed; transform: none;
  box-shadow: 0 3px 12px rgba(91,92,235,.22);
}

.btn-ghost {
  background: transparent;
  color: var(--text-sub);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-soft);
}

/* ---------- 5. Form Elements（透明输入背景 - 用户偏好） ---------- */
.form-input {
  width: 100%;
  height: 44px;
  padding: 0 16px;
  background: rgba(255, 255, 255, 0.65);  /* 透明背景 - 用户偏好 */
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  color: var(--text);
  font-size: 14px;
  transition: all .2s ease;
  backdrop-filter: blur(8px);
}
.form-input::placeholder { color: var(--text-disabled); }
.form-input:hover { border-color: var(--border-hover); }
.form-input:focus {
  border-color: var(--primary);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 0 0 4px rgba(91, 92, 235, 0.10);
}
.form-input:disabled { opacity: .55; cursor: not-allowed; }

/* ---------- 6. Navbar 玻璃拟态 ---------- */
.navbar {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px;
  height: 68px;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border-light);
  max-width: 100%;
  margin: 0 auto;
}
.navbar-brand {
  font-size: 20px; font-weight: 800;
  background: var(--primary-grad);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.01em;
}
.navbar-menu { display: flex; align-items: center; gap: 4px; }
.navbar-item {
  padding: 8px 16px;
  border-radius: var(--r-full);
  font-size: 14px; font-weight: 500;
  color: var(--text-sub);
  transition: all .18s ease;
}
.navbar-item:hover { background: var(--primary-soft); color: var(--primary); }
.navbar-item.active {
  background: var(--primary-grad);
  color: #fff;
  box-shadow: 0 4px 14px rgba(91,92,235,.3);
}
.navbar-right { display: flex; align-items: center; gap: 12px; }
.navbar-avatar {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--primary-grad);
  color: #fff;
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 600; font-size: 14px;
  box-shadow: 0 3px 10px rgba(91,92,235,.3);
  cursor: pointer;
  border: 2px solid #fff;
}

/* ---------- 7. Hero Section ---------- */
.hero {
  background: var(--primary-grad);
  color: #fff;
  padding: 56px 0;
  border-bottom-left-radius: var(--r-xl);
  border-bottom-right-radius: var(--r-xl);
  box-shadow: 0 12px 48px rgba(91, 92, 235, 0.18);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  right: -80px; top: -80px;
  width: 340px; height: 340px;
  border-radius: 50%;
  background: rgba(255,255,255,.08);
}
.hero::after {
  content: '';
  position: absolute;
  left: -60px; bottom: -120px;
  width: 300px; height: 300px;
  border-radius: 50%;
  background: rgba(255,255,255,.05);
}
.hero > .container { position: relative; z-index: 1; }
.hero-title {
  font-size: 40px; font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.hero-sub {
  margin-top: 12px;
  font-size: 16px;
  opacity: .9;
}

/* ---------- 8. Cards (通用卡片样式) ---------- */
.card {
  background: var(--surface);
  border-radius: var(--r-lg);
  padding: 28px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-1);
  transition: all .25s ease;
}
.card:hover { box-shadow: var(--shadow-2); }

/* ---------- 9. Chip / Category Bar（分类切换） ---------- */
.chip-bar {
  display: flex; flex-wrap: wrap; gap: 10px;
  padding: 24px 0 8px;
}
.chip {
  padding: 9px 20px;
  border-radius: var(--r-full);
  background: #fff;
  border: 1px solid var(--border);
  color: var(--text-sub);
  font-size: 14px; font-weight: 500;
  cursor: pointer;
  transition: all .2s ease;
  user-select: none;
}
.chip:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-1px);
}
.chip.active {
  background: var(--primary-grad);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(91,92,235,.35);
}

/* ---------- 10. Exam Grid（题库卡片列表） ---------- */
.exam-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding: 16px 0 40px;
}
@media (max-width: 1024px) { .exam-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 640px)  { .exam-grid { grid-template-columns: 1fr; } }

.exam-card {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 24px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-1);
  cursor: pointer;
  display: flex; gap: 16px; align-items: flex-start;
  transition: all .25s cubic-bezier(.4,0,.2,1);
}
.exam-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-3);
  border-color: rgba(91,92,235,.2);
}
.exam-icon {
  flex-shrink: 0;
  width: 56px; height: 56px;
  border-radius: var(--r-md);
  background: var(--primary-grad-soft);
  display: flex; align-items: center; justify-content: center;
  font-size: 28px;
}
.exam-name {
  font-size: 17px; font-weight: 700; color: var(--text);
  margin-bottom: 6px;
}
.exam-desc {
  font-size: 13px; color: var(--text-muted);
  margin-bottom: 12px;
  line-height: 1.5;
}
.exam-stats {
  display: flex; gap: 16px;
  font-size: 12px; color: var(--text-muted);
}
.exam-stats span {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 10px;
  background: var(--surface-2);
  border-radius: var(--r-full);
}

/* ---------- 11. Practice / 答题页 ---------- */
.practice-header {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 16px;
}
.progress-track {
  width: 100%;
  height: 6px;
  background: var(--border-light);
  border-radius: var(--r-full);
  overflow: hidden;
  margin-bottom: 24px;
}
.progress-fill {
  height: 100%;
  background: var(--primary-grad);
  border-radius: var(--r-full);
  transition: width .35s ease;
}
.question-card { padding: 8px 0 4px; }
.q-meta { display: flex; gap: 8px; margin-bottom: 16px; }
.q-tag {
  display: inline-block;
  padding: 4px 10px;
  font-size: 12px;
  border-radius: var(--r-full);
  font-weight: 500;
}
.q-type { background: var(--primary-soft); color: var(--primary); }
.q-diff { background: #FEF3C7; color: #92400E; }

.q-content {
  font-size: 16px;
  font-weight: 500;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: 24px;
}

.options { display: flex; flex-direction: column; gap: 12px; }
.option {
  display: flex; align-items: flex-start; gap: 14px;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: rgba(255,255,255,.75);
  cursor: pointer;
  transition: all .2s ease;
}
.option:hover {
  border-color: var(--primary);
  background: var(--primary-soft);
}
.option.selected {
  border: 2px solid var(--primary);
  background: var(--primary-soft);
  padding: 15px 17px;   /* 补偿 border 增加 1px */
}
.option.selected.correct {
  border-color: var(--success) !important;
  background: rgba(16, 185, 129, .08) !important;
}
.option.selected.wrong {
  border-color: var(--danger) !important;
  background: rgba(239, 68, 68, .08) !important;
}
.option.correct {
  border-color: var(--success) !important;
  background: rgba(16, 185, 129, .08) !important;
}
.option-key {
  flex-shrink: 0;
  width: 30px; height: 30px;
  border-radius: 50%;
  background: #fff;
  border: 1.5px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 14px;
  color: var(--text-sub);
}
.option.selected .option-key {
  background: var(--primary-grad);
  color: #fff;
  border-color: transparent;
}
.option.selected.correct .option-key { background: var(--success); }
.option.selected.wrong   .option-key { background: var(--danger); }
.option.correct .option-key { background: var(--success); color: #fff; border-color: transparent; }
.option-text {
  flex: 1;
  padding-top: 4px;
  font-size: 14px;
  color: var(--text);
  line-height: 1.65;
  word-break: break-word;
}

/* 解析区 */
.analysis-box {
  margin-top: 24px;
  border-radius: var(--r-md);
  padding: 20px;
  background: var(--surface-2);
  border: 1px solid var(--border-light);
}
.analysis-result {
  padding: 10px 16px;
  border-radius: var(--r-sm);
  font-weight: 600; font-size: 14px;
  margin-bottom: 16px;
}
.analysis-result.ok   { background: rgba(16,185,129,.10); color: var(--success); }
.analysis-result.fail { background: rgba(239,68,68,.10); color: var(--danger); }
.analysis-row { margin-bottom: 10px; font-size: 14px; }
.analysis-label { display: inline-block; font-weight: 600; color: var(--text-sub); margin-right: 6px; }
.analysis-content { margin-top: 12px; }
.analysis-text {
  font-size: 14px; color: var(--text);
  background: #fff;
  padding: 14px 16px;
  border-radius: var(--r-sm);
  line-height: 1.7;
  border: 1px solid var(--border-light);
}

/* AI 解析 Panel */
.ai-panel {
  margin-top: 24px;
  border-radius: var(--r-md);
  background: #fff;
  border: 1px solid var(--border);
  overflow: hidden;
  box-shadow: var(--shadow-1);
}
.ai-header {
  padding: 14px 20px;
  background: var(--primary-grad-soft);
  color: var(--primary-deep);
  font-weight: 600;
  display: flex; align-items: center;
  border-bottom: 1px solid var(--border-light);
}
.ai-body {
  padding: 16px 20px;
  max-height: 480px;
  overflow-y: auto;
  display: flex; flex-direction: column; gap: 12px;
}
.ai-msg { display: flex; }
.ai-msg.user { justify-content: flex-end; }
.ai-bubble {
  max-width: 88%;
  padding: 12px 16px;
  border-radius: var(--r-md);
  font-size: 14px; line-height: 1.7;
}
.ai-msg.assistant .ai-bubble {
  background: var(--surface-2);
  color: var(--text);
  border-top-left-radius: 4px;
  border: 1px solid var(--border-light);
}
.ai-msg.user .ai-bubble {
  background: var(--primary-grad);
  color: #fff;
  border-top-right-radius: 4px;
}
.ai-input-row {
  display: flex; gap: 10px;
  padding: 14px 20px;
  border-top: 1px solid var(--border-light);
  background: #fff;
}
.ai-input {
  flex: 1;
  height: 42px;
  padding: 0 14px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r-full);
  font-size: 14px;
  transition: all .2s ease;
}
.ai-input:focus {
  border-color: var(--primary);
  background: #fff;
  box-shadow: 0 0 0 4px rgba(91,92,235,.10);
}
.ai-send {
  width: 42px; height: 42px;
  border-radius: 50%;
  background: var(--primary-grad);
  color: #fff;
  box-shadow: var(--primary-shadow);
  display: flex; align-items: center; justify-content: center;
  transition: all .2s ease;
  flex-shrink: 0;
}
.ai-send:hover { transform: translateY(-1px); box-shadow: var(--primary-shadow-hover); }
.ai-send:disabled { opacity: .5; transform: none; cursor: not-allowed; }
.ai-send::before { content: '↗'; font-size: 18px; font-weight: 700; }
.ai-cursor {
  display: inline-block;
  width: 2px; height: 14px;
  background: currentColor;
  margin-left: 2px;
  animation: blink 1s steps(2) infinite;
  vertical-align: middle;
}
@keyframes blink { 50% { opacity: 0; } }

/* ---------- 12. Toast ---------- */
.toast {
  position: fixed;
  top: 24px; left: 50%;
  transform: translateX(-50%) translateY(-20px);
  padding: 12px 24px;
  background: rgba(17, 24, 39, .92);
  color: #fff;
  border-radius: var(--r-full);
  font-size: 14px;
  z-index: 10000;
  opacity: 0;
  pointer-events: none;
  transition: all .3s cubic-bezier(.4,0,.2,1);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-3);
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast.error  { background: rgba(239, 68, 68, .95); }
.toast.success { background: rgba(16, 185, 129, .95); }

/* ---------- 13. Empty & Loading ---------- */
.empty {
  padding: 60px 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
}
.empty-icon { font-size: 44px; margin-bottom: 12px; opacity: .6; }
.loading-dots {
  display: inline-flex; gap: 6px;
  align-items: center; justify-content: center;
}
.loading-dots span {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--primary);
  animation: dotPulse 1.2s ease-in-out infinite;
}
.loading-dots span:nth-child(2) { animation-delay: .15s; opacity: .75; }
.loading-dots span:nth-child(3) { animation-delay: .3s; opacity: .5; }
@keyframes dotPulse {
  0%, 80%, 100% { transform: scale(.6); opacity: .5; }
  40% { transform: scale(1.1); opacity: 1; }
}

/* ---------- 14. Beian Footer（备案号底部中央悬挂） ---------- */
.beian-footer {
  text-align: center;
  padding: 28px 16px 32px;
  font-size: 12px;
  color: var(--text-disabled);
}
.beian-footer a {
  color: var(--text-muted);
  transition: color .2s ease;
}
.beian-footer a:hover { color: var(--primary); }

/* ---------- 15. Stats Overview（数据页 KPI 卡片） ---------- */
.stat-grid {
  display: grid; gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  padding: 24px 0;
}
.stat-card {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 24px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-1);
  position: relative;
  overflow: hidden;
  transition: all .25s ease;
}
.stat-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-2); }
.stat-card::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 4px;
  background: var(--primary-grad);
}
.stat-card.c1::before { background: linear-gradient(180deg,#5B5CEB,#7C3AED); }
.stat-card.c2::before { background: linear-gradient(180deg,#10B981,#059669); }
.stat-card.c3::before { background: linear-gradient(180deg,#F59E0B,#D97706); }
.stat-card.c4::before { background: linear-gradient(180deg,#3B82F6,#2563EB); }
.stat-card.c5::before { background: linear-gradient(180deg,#EC4899,#DB2777); }
.stat-card.c6::before { background: linear-gradient(180deg,#8B5CF6,#7C3AED); }
.stat-label {
  font-size: 13px; color: var(--text-muted);
  font-weight: 500;
  margin-bottom: 12px;
}
.stat-num {
  font-size: 32px; font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.stat-sub {
  font-size: 12px; color: var(--text-muted);
  margin-top: 8px;
}

/* ---------- 16. Wrong Book / Tables ---------- */
.data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: #fff;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-1);
}
.data-table th, .data-table td {
  padding: 14px 20px;
  text-align: left;
  font-size: 14px;
  border-bottom: 1px solid var(--border-light);
}
.data-table th {
  background: var(--surface-2);
  color: var(--text-sub);
  font-weight: 600;
  font-size: 13px;
}
.data-table tr:last-child td { border-bottom: none; }
.data-table tr:hover td { background: var(--primary-soft); }

/* ---------- 17. Chapter Tree（章节树） ---------- */
.chapter-tree {
  background: #fff;
  border-radius: var(--r-lg);
  padding: 12px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-1);
}
.chapter-node {
  padding: 12px 16px;
  border-radius: var(--r-sm);
  cursor: pointer;
  display: flex; align-items: center; justify-content: space-between;
  transition: all .18s ease;
}
.chapter-node:hover {
  background: var(--primary-soft);
  color: var(--primary);
}
.chapter-node.active {
  background: var(--primary-grad);
  color: #fff;
}
.chapter-name { font-weight: 500; font-size: 14px; }
.chapter-count {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: var(--r-full);
  background: var(--surface-2);
  color: var(--text-muted);
}
.chapter-node.active .chapter-count { background: rgba(255,255,255,.2); color: #fff; }
.children-nodes { padding-left: 20px; border-left: 1px dashed var(--border-light); margin-left: 14px; }

/* ---------- 18. 首页组件：Hero 搜索框 ---------- */
.hero-search {
  width: 100%;
  max-width: 560px;
  margin-top: 28px;
  height: 52px;
  padding: 0 22px;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(255,255,255,0.4);
  border-radius: var(--r-full);
  font-size: 15px;
  color: var(--text);
  transition: all .25s cubic-bezier(.4,0,.2,1);
  box-shadow: 0 8px 28px rgba(0,0,0,0.12);
}
.hero-search::placeholder { color: var(--text-muted); }
.hero-search:hover { box-shadow: 0 10px 36px rgba(0,0,0,0.16); transform: translateY(-1px); }
.hero-search:focus {
  outline: none;
  box-shadow: 0 0 0 4px rgba(255,255,255,0.25), 0 12px 40px rgba(0,0,0,0.18);
}

/* ---------- 19. 首页组件：Quick Grid（快速入口卡片） ---------- */
.quick-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: -34px;  /* 向上贴入 Hero 底部，形成悬浮效果 */
  position: relative;
  z-index: 2;
  margin-bottom: 8px;
}
@media (max-width: 960px)   { .quick-grid { grid-template-columns: repeat(2, 1fr); margin-top: -20px; } }
@media (max-width: 520px)   { .quick-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; } }

.quick-card {
  display: flex; align-items: center; gap: 14px;
  background: #fff;
  padding: 20px 22px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border-light);
  box-shadow: 0 4px 20px rgba(17, 24, 39, 0.06);
  cursor: pointer;
  transition: all .25s cubic-bezier(.4,0,.2,1);
}
.quick-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 44px rgba(17, 24, 39, 0.10);
  border-color: rgba(91,92,235,.2);
}
.quick-icon {
  flex-shrink: 0;
  width: 48px; height: 48px;
  border-radius: var(--r-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 24px;
  transition: transform .25s ease;
}
.quick-card:hover .quick-icon { transform: scale(1.08); }
.quick-label {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}


/* ---------- 19b. Chapter Item / Sub Item（章节列表行 + 子行） ---------- */
.chapter-list { display: flex; flex-direction: column; }
.chapter-item {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 16px 20px;
  border-bottom: 1px solid var(--border-light);
  cursor: pointer; transition: all .18s cubic-bezier(.4,0,.2,1);
}
.chapter-item:last-child { border-bottom: none; }
.chapter-item:hover {
  background: linear-gradient(90deg, rgba(91,92,235,0.06) 0%, transparent 80%);
  border-left: 3px solid var(--primary);
}
.chapter-item:hover .chapter-chevron { color: var(--primary); transform: translateX(2px); }
.chapter-item-title {
  display: flex; align-items: center; gap: 12px;
  font-weight: 600; font-size: 15px; color: var(--text);
}
.chapter-item-title .chapter-bullet {
  width: 24px; height: 24px; border-radius: 6px;
  background: #ede9fe; color: #7c3aed; font-size: 13px;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.chapter-item-meta { display: flex; align-items: center; gap: 12px; color: var(--text-muted); font-size: 13px; }
.chapter-count {
  padding: 3px 10px; border-radius: 12px;
  background: var(--bg-muted); font-size: 12px; font-weight: 500;
  color: var(--text-muted);
}
.chapter-item:hover .chapter-count { background: rgba(91,92,235,0.1); color: var(--primary); }
.chapter-chevron { color: var(--text-muted); transition: all .18s ease; }

/* 子章节项 */
.sub-item {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 20px 12px 56px; gap: 16px;
  border-bottom: 1px solid var(--border-light);
  cursor: pointer; transition: all .18s ease;
  font-size: 14px; color: var(--text-light);
}
.sub-item:last-child { border-bottom: none; }
.sub-item::before {
  content: '└─'; color: var(--border); font-size: 12px;
  margin-right: 8px; color: #b4b4c0;
}
.sub-item:hover { background: var(--bg-muted); color: var(--primary); }
.sub-item .sub-name { color: inherit; }
.sub-item .sub-count {
  padding: 2px 8px; border-radius: 10px;
  background: var(--bg-muted); font-size: 12px; color: var(--text-muted);
}
.sub-item:hover .sub-count { background: rgba(91,92,235,0.1); color: var(--primary); }

/* ---------- 20. Responsive ---------- */
@media (max-width: 860px) {
  .navbar { padding: 0 16px; height: 60px; }
  .navbar-menu { gap: 0; }
  .navbar-item { padding: 6px 12px; font-size: 13px; }
  .hero { padding: 36px 0; border-radius: 0 0 var(--r-lg) var(--r-lg); }
  .hero-title { font-size: 28px; }
  .hero-sub { font-size: 14px; }
  .card { padding: 20px 16px; }
  .hero-search { height: 46px; margin-top: 20px; }
}