/* =====================================================
   共享增强层 enhance.css
   功能：暗色模式 / 返回顶部 / 面包屑 / 章内目录 / 站内搜索 / 掌握标记 / 通用动效
   适用范围：study-hub 四门课程站 + 聚合站
   ===================================================== */

/* ---------- 暗色模式变量 ---------- */
html[data-theme="dark"] {
  --bg: #0f1420;
  --card: #161d2c;
  --ink: #e7ecf5;
  --muted: #8b98ad;
  --line: #263247;
  --primary-soft: rgba(37, 99, 235, .14);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, .45);
  --shadow-lg: 0 18px 44px rgba(0, 0, 0, .55);
  color-scheme: dark;
}
html[data-theme="dark"] body {
  background: var(--bg);
  background-image: radial-gradient(1100px 340px at 85% -80px, rgba(37, 99, 235, .1), transparent 60%);
  color: var(--ink);
}
html[data-theme="dark"] a { color: var(--accent, var(--primary)); }
html[data-theme="dark"] .topbar {
  background: rgba(15, 20, 32, .86);
  border-bottom-color: var(--line);
}
html[data-theme="dark"] .site-footer { background: rgba(15, 20, 32, .7); }
html[data-theme="dark"] .main-nav a:hover { background: rgba(255, 255, 255, .06); color: var(--ink); }
html[data-theme="dark"] .card,
html[data-theme="dark"] .q-item,
html[data-theme="dark"] .chapter-card,
html[data-theme="dark"] .point,
html[data-theme="dark"] .paper-block,
html[data-theme="dark"] .type-block,
html[data-theme="dark"] .info-chip,
html[data-theme="dark"] .tips,
html[data-theme="dark"] .vocab-progress,
html[data-theme="dark"] .quiz-toolbar select,
html[data-theme="dark"] .search-input {
  background: var(--card);
  border-color: var(--line);
  color: var(--ink);
}
html[data-theme="dark"] .point--must { background: linear-gradient(180deg, rgba(225, 29, 72, .18), var(--card) 42%); }
html[data-theme="dark"] .point--hot { background: linear-gradient(180deg, rgba(245, 158, 11, .16), var(--card) 42%); }
html[data-theme="dark"] .chapter-card.done { background: linear-gradient(160deg, var(--card), rgba(16, 185, 129, .12)); }
html[data-theme="dark"] table { background: var(--card); border-color: var(--line); }
html[data-theme="dark"] th { background: linear-gradient(180deg, #1c2538, #1a2233); color: var(--ink); }
html[data-theme="dark"] tbody tr:nth-child(even) td,
html[data-theme="dark"] tr:nth-child(even) { background: #141b29; }
html[data-theme="dark"] .explain { background: #1a2233; border-color: var(--line); }
html[data-theme="dark"] .short-answer .answer-box { background: rgba(16, 185, 129, .12); border-color: rgba(16, 185, 129, .3); }
html[data-theme="dark"] .option:hover,
html[data-theme="dark"] .option.selected { background: rgba(37, 99, 235, .15); }
html[data-theme="dark"] .option.correct { background: rgba(16, 185, 129, .15); border-color: var(--ok); }
html[data-theme="dark"] .option.wrong { background: rgba(239, 68, 68, .15); border-color: var(--err); }
html[data-theme="dark"] .flash-card { background: linear-gradient(165deg, #161d2c, rgba(37, 99, 235, .12)); border-color: var(--line); }
html[data-theme="dark"] .word-card { background: linear-gradient(165deg, #161d2c, rgba(37, 99, 235, .12)); border-color: var(--primary); }
html[data-theme="dark"] .word-ex { background: rgba(255, 255, 255, .05); color: #9fb0c9; }
html[data-theme="dark"] .point .ex { background: linear-gradient(160deg, rgba(37, 99, 235, .12), var(--card)); border-color: color-mix(in srgb, var(--primary) 30%, transparent); }
html[data-theme="dark"] .plain { background: linear-gradient(135deg, rgba(37, 99, 235, .15), var(--card)); color: var(--ink); }
html[data-theme="dark"] .plain-tag { background: rgba(37, 99, 235, .3); }
html[data-theme="dark"] .mnemonic { background: linear-gradient(160deg, rgba(245, 158, 11, .14), var(--card)); border-color: rgba(245, 158, 11, .4); color: #e5c891; }
html[data-theme="dark"] .mnemonic b { color: #f59e0b; }
html[data-theme="dark"] .analogy { background: linear-gradient(160deg, rgba(37, 99, 235, .12), var(--card)); color: #a9bdd9; }
html[data-theme="dark"] .miss-item { background: rgba(239, 68, 68, .15); border-color: rgba(239, 68, 68, .3); }
html[data-theme="dark"] .must-list { background: linear-gradient(160deg, var(--card), rgba(225, 29, 72, .1)); border-color: rgba(225, 29, 72, .35); }
html[data-theme="dark"] .type-pct { background: rgba(37, 99, 235, .2); }
html[data-theme="dark"] .btn.ghost { background: var(--card); color: var(--primary); }
html[data-theme="dark"] .btn.err { background: var(--card); }
html[data-theme="dark"] .progress-detail .bar { background: #1e2839; }
html[data-theme="dark"] .v-row:nth-child(even) { background: #141b29; }
html[data-theme="dark"] .menu-btn,
html[data-theme="dark"] .theme-toggle,
html[data-theme="dark"] .search-toggle {
  background: var(--card);
  border-color: var(--line);
  color: var(--ink);
}
html[data-theme="dark"] .main-nav { background: var(--card); }
html[data-theme="dark"] .paper-block h3 { background: linear-gradient(90deg, #1a2233, var(--card)); }
html[data-theme="dark"] .graph { background: #111827; border-color: #263247; }
html[data-theme="dark"] .graph .g-axis { stroke: #3a4a63; }
html[data-theme="dark"] .graph .g-lbl { fill: #6b7a93; }
html[data-theme="dark"] .limit-anim,
html[data-theme="dark"] .squeeze-anim,
html[data-theme="dark"] .inf-anim,
html[data-theme="dark"] .bf-wrap,
html[data-theme="dark"] .map-anim,
html[data-theme="dark"] .codeflow-anim,
html[data-theme="dark"] .se-anim,
html[data-theme="dark"] .sent-anim { background: #141b29; border-color: var(--line); }

/* ---------- 导航栏精致化 ---------- */
.topbar { position: relative; }
.topbar::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--primary, #2563eb), var(--accent, #7c3aed), var(--ok, #10b981));
  opacity: .8;
}
.brand { position: relative; padding-left: 26px; }
.brand::before {
  content: "学";
  position: absolute;
  left: 0; top: 50%;
  transform: translateY(-50%);
  width: 20px; height: 20px;
  font-size: 11px;
  font-weight: 900;
  line-height: 20px;
  text-align: center;
  color: #fff;
  border-radius: 7px;
  background: linear-gradient(135deg, var(--primary, #2563eb), var(--accent, #7c3aed));
  box-shadow: 0 2px 6px color-mix(in srgb, var(--primary, #2563eb) 40%, transparent);
}
.main-nav a.active {
  box-shadow: 0 4px 14px color-mix(in srgb, var(--primary, #2563eb) 45%, transparent);
  transform: translateY(-1px);
}
html[data-theme="dark"] .main-nav a.active { box-shadow: 0 4px 16px rgba(37, 99, 235, .5); }
html[data-theme="dark"] .brand::before { box-shadow: 0 2px 8px rgba(37, 99, 235, .6); }

/* ---------- 返回顶部按钮 ---------- */
.backtop {
  position: fixed;
  right: 18px;
  bottom: 22px;
  z-index: 999;
  width: 42px;
  height: 42px;
  border: none;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary, #2563eb), var(--accent, #7c3aed));
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .25s ease, transform .25s ease, visibility .25s;
  box-shadow: 0 8px 20px rgba(20, 30, 60, .35);
}
.backtop.show { opacity: 1; visibility: visible; transform: translateY(0); }
.backtop:hover { transform: translateY(-3px); }
@media (prefers-reduced-motion: reduce) { .backtop { transition: none; } }

/* ---------- 面包屑 ---------- */
.crumbs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
  margin: 2px 0 14px;
}
.crumbs a {
  color: var(--muted);
  text-decoration: none;
  padding: 2px 8px;
  border-radius: 999px;
  transition: all .15s ease;
}
.crumbs a:hover { background: var(--primary-soft); color: var(--primary); }
.crumbs .sep { opacity: .5; }
.crumbs .cur { font-weight: 700; color: var(--ink); }

/* ---------- 章内目录 ---------- */
.toc-wrap {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 4px solid var(--primary, #2563eb);
  border-radius: var(--radius, 14px);
  padding: 12px 16px;
  margin: 12px 0 18px;
  box-shadow: var(--shadow-sm);
}
.toc-title {
  font-size: 13px;
  font-weight: 800;
  color: var(--primary, #2563eb);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}
.toc-title .toc-toggle { font-size: 12px; opacity: .7; }
.toc-list { margin: 10px 0 0; padding: 0; list-style: none; display: grid; gap: 4px; }
.toc-list.collapsed { display: none; }
.toc-list li { margin: 0; }
.toc-list a {
  display: block;
  padding: 5px 10px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  transition: all .14s ease;
  border-left: 2px solid transparent;
}
.toc-list a:hover { background: var(--primary-soft); color: var(--primary); }
.toc-list a.active { background: var(--primary-soft); color: var(--primary); border-left-color: var(--primary); font-weight: 700; }
h2[id], h3[id] { scroll-margin-top: 68px; }

/* ---------- 站内搜索 ---------- */
.search-bar {
  display: none;
  align-items: center;
  gap: 8px;
  margin: 12px 0 16px;
}
.search-bar.open { display: flex; }
.search-bar input {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  font-size: 14px;
  background: var(--card);
  color: var(--ink);
  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease;
}
.search-bar input:focus { border-color: var(--primary, #2563eb); box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary, #2563eb) 18%, transparent); }
.search-results { display: none; }
.search-results.open { display: block; }
.search-results .sr-count { font-size: 12px; color: var(--muted); margin-bottom: 8px; }
.sr-item {
  display: block;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 10px;
  margin-bottom: 8px;
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
  transition: all .15s ease;
}
.sr-item:hover { border-color: var(--primary, #2563eb); box-shadow: var(--shadow-md); transform: translateY(-1px); }
.sr-item .sr-ch { font-size: 11px; color: var(--primary, #2563eb); font-weight: 800; margin-right: 6px; }
.sr-item .sr-title { font-weight: 700; font-size: 14px; }
.sr-item .sr-snip { font-size: 12px; color: var(--muted); margin-top: 3px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.sr-item mark { background: rgba(245, 158, 11, .35); color: inherit; border-radius: 3px; padding: 0 2px; }

.search-toggle {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  border-radius: 999px;
  padding: 5px 13px;
  font-size: 13px;
  cursor: pointer;
  transition: all .16s ease;
}
.search-toggle:hover { color: var(--primary); border-color: var(--primary); }

/* ---------- 主题切换按钮 ---------- */
.theme-toggle {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  border-radius: 999px;
  padding: 5px 13px;
  font-size: 13px;
  cursor: pointer;
  transition: all .16s ease;
  white-space: nowrap;
}
.theme-toggle:hover { color: var(--primary); border-color: var(--primary); }

/* ---------- 掌握标记 ---------- */
.point { position: relative; }
.master-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 3;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  font-size: 12px;
  border-radius: 999px;
  padding: 3px 11px;
  cursor: pointer;
  opacity: 0;
  transition: all .18s ease;
}
.point:hover .master-btn { opacity: 1; }
.master-btn:hover { border-color: var(--ok, #10b981); color: var(--ok, #10b981); }
.master-btn.on { opacity: 1; background: linear-gradient(120deg, #10b981, #059669); border-color: transparent; color: #fff; box-shadow: 0 3px 8px rgba(16, 185, 129, .4); }
.point.mastered { border-left-color: var(--ok, #10b981); }
.point.mastered::after {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, #10b981, #34d399);
}
@media (max-width: 720px) { .master-btn { opacity: 1; } }

/* ---------- 暗色下掌握按钮配色跟随 ---------- */
html[data-theme="dark"] .master-btn { background: var(--card); border-color: var(--line); color: var(--muted); }

/* ---------- 聚合站：课程卡片进度 ---------- */
.course-card .c-progress {
  height: 6px;
  background: #eceef3;
  border-radius: 999px;
  overflow: hidden;
  margin-top: 2px;
}
.course-card .c-progress > div {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--theme), color-mix(in srgb, var(--theme) 70%, #fff));
  width: 0;
  transition: width .6s ease;
}
.course-card .c-progress-text { font-size: 11px; color: var(--muted); margin-top: 3px; }
html[data-theme="dark"] .course-card .c-progress { background: #1e2839; }

/* ---------- 首页 Hero 面板 ---------- */
.hero-panel {
  position: relative;
  overflow: hidden;
  border-radius: 22px;
  margin: 4px 0 22px;
  padding: 34px 26px 30px;
  color: #fff;
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary, #2563eb) 78%, #1e1b4b), color-mix(in srgb, var(--primary, #2563eb) 55%, #312e81));
  box-shadow: 0 18px 42px color-mix(in srgb, var(--primary, #2563eb) 38%, transparent);
  animation: heroIn .5s ease backwards;
}
.hero-inner { position: relative; z-index: 2; max-width: 720px; }
.hero-code {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  opacity: .85;
  font-weight: 700;
}
.hero-title {
  margin: 0 0 12px !important;
  font-size: 30px !important;
  font-weight: 900;
  letter-spacing: .5px;
  line-height: 1.2;
}
.hero-chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 16px; }
.hero-chip {
  font-size: 12px;
  line-height: 1.4;
  background: rgba(255, 255, 255, .16);
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: 999px;
  padding: 4px 12px;
  backdrop-filter: blur(4px);
}
.hero-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin: 0 0 16px; max-width: 480px; }
.hs-item {
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 14px;
  padding: 12px 10px;
  text-align: center;
  backdrop-filter: blur(6px);
  transition: transform .16s ease, background .16s ease;
}
.hs-item:hover { transform: translateY(-3px); background: rgba(255, 255, 255, .18); }
.hs-item b { display: block; font-size: 24px; font-weight: 900; line-height: 1.1; }
.hs-item span { font-size: 12px; opacity: .85; }
.hero-progress { margin: 0 0 18px; max-width: 480px; }
.hp-bar { height: 8px; background: rgba(255, 255, 255, .22); border-radius: 999px; overflow: hidden; }
.hp-bar > div { height: 100%; background: #fff; border-radius: 999px; transition: width .6s ease; }
.hp-text { display: block; margin-top: 6px; font-size: 12px; opacity: .9; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-actions .btn {
  background: #fff;
  color: color-mix(in srgb, var(--primary, #2563eb) 85%, #000);
  box-shadow: 0 8px 20px rgba(0, 0, 0, .2);
}
.hero-actions .btn:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(0, 0, 0, .26); }
.hero-actions .btn.ghost { background: rgba(255, 255, 255, .14); color: #fff; border: 1px solid rgba(255, 255, 255, .4); }
.hero-actions .btn.ghost:hover { background: rgba(255, 255, 255, .24); }
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
  pointer-events: none;
}
.hero-orb-a { width: 240px; height: 240px; right: -60px; top: -90px; background: rgba(255, 255, 255, .12); }
.hero-orb-b { width: 160px; height: 160px; right: 90px; bottom: -70px; background: rgba(255, 255, 255, .08); }
.hero-orb-c { width: 90px; height: 90px; left: 36%; top: -40px; background: rgba(255, 255, 255, .1); }
@keyframes heroIn { from { opacity: 0; transform: translateY(14px) scale(.99); } to { opacity: 1; transform: none; } }
html[data-theme="dark"] .hero-panel {
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary, #2563eb) 70%, #0b1020), #131a2e 75%);
}

/* ---------- 章节卡片强化 ---------- */
.chapter-grid .chapter-card {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--card), color-mix(in srgb, var(--primary, #2563eb) 4%, var(--card)));
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.chapter-grid .chapter-card::before {
  content: attr(data-index);
  position: absolute;
  right: -8px;
  top: -18px;
  font-size: 64px;
  font-weight: 900;
  line-height: 1;
  color: color-mix(in srgb, var(--primary, #2563eb) 12%, transparent);
  pointer-events: none;
}
.chapter-grid .chapter-card:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: 0 16px 32px color-mix(in srgb, var(--primary, #2563eb) 22%, rgba(20, 30, 60, .1));
}
.chapter-grid .chapter-card .num {
  display: inline-block;
  background: linear-gradient(120deg, var(--primary), var(--accent, #7c3aed));
  color: #fff;
  border-radius: 999px;
  padding: 2px 10px;
  font-size: 11px;
}
.chapter-grid .chapter-card.done::after {
  content: "✓ 已完成";
  position: absolute;
  right: 10px;
  top: 10px;
  font-size: 11px;
  font-weight: 800;
  color: var(--ok, #10b981);
  background: color-mix(in srgb, var(--ok, #10b981) 14%, #fff);
  border: 1px solid color-mix(in srgb, var(--ok, #10b981) 35%, transparent);
  border-radius: 999px;
  padding: 2px 9px;
}
html[data-theme="dark"] .chapter-grid .chapter-card.done::after { background: color-mix(in srgb, var(--ok, #10b981) 18%, var(--card)); }
html[data-theme="dark"] .chapter-grid .chapter-card { background: linear-gradient(180deg, var(--card), color-mix(in srgb, var(--primary, #2563eb) 8%, var(--card))); }

/* ---------- 知识点卡片强化 ---------- */
.point {
  position: relative;
  transition: box-shadow .18s ease, transform .18s ease, border-color .18s ease;
}
.point:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px color-mix(in srgb, var(--primary, #2563eb) 16%, rgba(20, 30, 60, .08));
}
.point h4 { padding-right: 96px; }
.point .lv { box-shadow: 0 3px 8px rgba(0, 0, 0, .16); }
html[data-theme="dark"] .point h4 { padding-right: 96px; }

/* ---------- 实用工具面板按钮 ---------- */
.enh-panels { display: flex; gap: 4px; flex-wrap: wrap; }
.enh-panel-btn {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  border-radius: 999px;
  padding: 5px 12px;
  font-size: 13px;
  cursor: pointer;
  transition: all .16s ease;
  white-space: nowrap;
}
.enh-panel-btn:hover {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(120deg, var(--primary, #2563eb), var(--accent, #7c3aed));
  box-shadow: 0 4px 12px color-mix(in srgb, var(--primary, #2563eb) 40%, transparent);
}
html[data-theme="dark"] .enh-panel-btn { background: var(--card); border-color: var(--line); color: var(--muted); }
html[data-theme="dark"] .enh-panel-btn:hover { color: #fff; }

/* ---------- 全屏面板 ---------- */
.enh-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.enh-overlay.open { display: flex; }
.eo-mask {
  position: absolute;
  inset: 0;
  background: rgba(10, 16, 28, .55);
  backdrop-filter: blur(3px);
  -webkit-backdrop-filter: blur(3px);
}
.eo-panel {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 760px;
  max-height: 86vh;
  display: flex;
  flex-direction: column;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 30px 70px rgba(10, 16, 28, .5);
  animation: eoIn .25s ease backwards;
}
@keyframes eoIn { from { opacity: 0; transform: translateY(18px) scale(.98); } to { opacity: 1; transform: none; } }
.eo-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
}
.eo-title { margin: 0; font-size: 17px; font-weight: 800; }
.eo-close {
  border: none;
  background: transparent;
  font-size: 24px;
  line-height: 1;
  color: var(--muted);
  cursor: pointer;
  padding: 2px 8px;
  border-radius: 8px;
  transition: all .15s ease;
}
.eo-close:hover { background: var(--primary-soft); color: var(--primary); }
.eo-body {
  padding: 18px 20px 24px;
  overflow-y: auto;
  overscroll-behavior: contain;
}
.enh-lock { overflow: hidden; }
.eo-empty {
  color: var(--muted);
  font-size: 14px;
  padding: 20px 4px;
  text-align: center;
}
.enh-toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%) translateY(20px);
  z-index: 3000;
  background: #111a2c;
  color: #fff;
  font-size: 13px;
  padding: 9px 18px;
  border-radius: 999px;
  opacity: 0;
  visibility: hidden;
  transition: all .25s ease;
  box-shadow: 0 10px 26px rgba(0, 0, 0, .35);
  max-width: 80vw;
}
.enh-toast.show { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(0); }

/* ---------- 错题本 ---------- */
.ew-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
  font-size: 13px;
  color: var(--muted);
}
.ew-item {
  border: 1px solid var(--line);
  border-left: 4px solid var(--err, #ef4444);
  border-radius: 12px;
  padding: 12px 14px;
  margin-bottom: 10px;
  background: var(--card);
  box-shadow: var(--shadow-sm);
}
.ew-tags { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; flex-wrap: wrap; }
.ew-type {
  font-size: 11px;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(120deg, #ef4444, #f97316);
  border-radius: 999px;
  padding: 1px 9px;
  line-height: 19px;
}
.ew-ch { font-size: 12px; color: var(--primary, #2563eb); font-weight: 700; }
.ew-item time { font-size: 11px; color: var(--muted); margin-left: auto; }
.ew-text { font-size: 14px; margin-bottom: 8px; line-height: 1.6; }
.ew-actions { display: flex; gap: 8px; }

/* ---------- 模拟考试 ---------- */
.em-start { text-align: center; padding: 26px 10px; }
.em-start h3 { margin: 0 0 10px; font-size: 20px; }
.em-start p { color: var(--muted); font-size: 14px; margin: 0 0 20px; }
.em-meta {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 14px;
  padding: 10px 14px;
  background: var(--primary-soft);
  border-radius: 10px;
}
.em-meta b { color: var(--primary, #2563eb); font-size: 18px; font-variant-numeric: tabular-nums; }
.em-q {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 13px 15px;
  margin-bottom: 12px;
  background: var(--card);
  transition: border-color .15s ease;
}
.em-q.em-right { border-left: 4px solid var(--ok, #10b981); }
.em-q.em-wrong { border-left: 4px solid var(--err, #ef4444); }
.em-q.em-skip { border-left: 4px solid var(--warn, #d97706); opacity: .75; }
.em-qhead { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; font-size: 12px; color: var(--muted); }
.em-qtext { font-size: 14px; margin-bottom: 10px; line-height: 1.6; }
.em-options { display: flex; flex-direction: column; gap: 7px; }
.em-opt {
  display: flex;
  align-items: flex-start;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--card);
  cursor: pointer;
  font-size: 14px;
  color: var(--ink);
  text-align: left;
  transition: all .14s ease;
  font-family: inherit;
}
.em-opt:hover { border-color: var(--primary, #2563eb); background: var(--primary-soft); }
.em-opt.sel {
  border-color: var(--primary, #2563eb);
  background: var(--primary-soft);
  box-shadow: inset 0 0 0 1px var(--primary, #2563eb);
  font-weight: 600;
}
.em-opt .letter { font-weight: 800; color: var(--primary, #2563eb); min-width: 18px; }
.em-answer {
  margin-top: 10px;
  padding: 10px 13px;
  border-radius: 10px;
  background: #f8fafc;
  border: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink);
}
.em-score {
  margin-bottom: 16px;
  padding: 16px 18px;
  border-radius: 14px;
  text-align: center;
  background: linear-gradient(135deg, var(--primary-soft), var(--card));
  border: 1px solid color-mix(in srgb, var(--primary, #2563eb) 25%, transparent);
}
.em-score-big { font-size: 34px; font-weight: 900; color: var(--primary, #2563eb); }
.em-score-detail { font-size: 13px; color: var(--muted); margin-top: 4px; }
.em-score-bar {
  height: 8px;
  background: #eceef3;
  border-radius: 999px;
  overflow: hidden;
  margin-top: 12px;
}
.em-score-bar > div { height: 100%; background: linear-gradient(90deg, var(--ok, #10b981), var(--primary, #2563eb)); border-radius: 999px; transition: width .5s ease; }

/* ---------- 速查表 ---------- */
.es-search {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  font-size: 14px;
  margin-bottom: 16px;
  background: var(--card);
  color: var(--ink);
  outline: none;
  transition: all .15s ease;
}
.es-search:focus { border-color: var(--primary, #2563eb); box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary, #2563eb) 18%, transparent); }
.es-list { display: flex; flex-direction: column; }
.es-row {
  display: grid;
  grid-template-columns: 130px 110px 52px 1fr;
  gap: 8px;
  padding: 8px 4px;
  border-bottom: 1px solid var(--line);
  font-size: 13px;
  align-items: baseline;
}
.es-row:nth-child(even) { background: #fafbfd; }
.es-word { font-weight: 800; color: var(--ink); }
.es-ipa { color: var(--muted); font-family: Consolas, monospace; }
.es-pos { color: var(--primary, #2563eb); }
.es-cn { color: var(--ink); }
.es-ex { color: var(--muted); grid-column: 1 / 5; font-size: 12px; }
.es-cards { display: flex; flex-direction: column; gap: 14px; }
.es-ch h3 {
  font-size: 14px;
  margin: 0 0 8px;
  padding: 6px 12px;
  background: linear-gradient(90deg, var(--primary-soft), transparent);
  border-left: 3px solid var(--primary, #2563eb);
  border-radius: 6px;
}
.es-card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 13px;
  margin-bottom: 8px;
  background: var(--card);
  transition: all .14s ease;
}
.es-card:hover { border-color: var(--primary, #2563eb); box-shadow: var(--shadow-md); }
.es-front { font-weight: 700; font-size: 13px; }
.es-back { color: var(--muted); font-size: 13px; margin-top: 4px; line-height: 1.6; }
html[data-theme="dark"] .es-row:nth-child(even) { background: #141b29; }
html[data-theme="dark"] .em-answer { background: #1a2233; border-color: var(--line); }
html[data-theme="dark"] .em-score-bar { background: #1e2839; }

/* ---------- 页面顶部毛玻璃过渡 ---------- */
.fade-page { animation: enhanceFade .35s ease; }
@keyframes enhanceFade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) { .fade-page { animation: none; } }

/* ---------- 打印优化 ---------- */
@media print {
  .topbar, .menu-btn, .backtop, .theme-toggle, .search-toggle,
  .search-bar, .master-btn, .crumbs .sep, .toc-toggle, .flash-hint,
  .enh-panels, .enh-overlay, .enh-toast { display: none !important; }
  body { background: #fff !important; }
  body.enh-lock { overflow: visible !important; }
}

/* =====================================================
   视觉升级 V2
   精排 / 微交互 / 纹理与光泽 / 自定义滚动条
   ===================================================== */

/* ---------- 全局排版精排 ---------- */
html {
  scroll-behavior: smooth;
}
body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
h1, h2, h3, h4, .c-title, .hero-title, .brand, .word-big, .em-score-big {
  text-wrap: balance;
}
::selection {
  background: color-mix(in srgb, var(--primary, #2563eb) 22%, transparent);
  color: inherit;
}

/* ---------- 自定义滚动条 ---------- */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--muted, #6b7280) 38%, transparent);
  border-radius: 999px;
  border: 2px solid transparent;
  background-clip: padding-box;
}
::-webkit-scrollbar-thumb:hover { background-color: color-mix(in srgb, var(--primary, #2563eb) 55%, transparent); }
html[data-theme="dark"] ::-webkit-scrollbar-thumb { background-color: color-mix(in srgb, #8b98ad 45%, transparent); }
html[data-theme="dark"] ::-webkit-scrollbar-thumb:hover { background-color: color-mix(in srgb, var(--primary, #2563eb) 65%, transparent); }

/* ---------- 导航栏：滑动指示条 ---------- */
.topbar { box-shadow: 0 1px 0 var(--line), 0 10px 30px -18px rgba(20, 30, 60, .35); }
.main-nav a { position: relative; }
.main-nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 1px;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background: currentColor;
  opacity: .85;
  transform: translateX(-50%);
  transition: width .22s ease;
}
.main-nav a:hover::after { width: 60%; }
.main-nav a.active::after { width: 70%; background: #fff; }
html[data-theme="dark"] .main-nav a.active::after { background: #fff; }

/* 品牌图标：呼吸光晕 */
.brand::before {
  animation: brandPulse 3.2s ease-in-out infinite;
}
@keyframes brandPulse {
  0%, 100% { box-shadow: 0 2px 6px color-mix(in srgb, var(--primary, #2563eb) 40%, transparent); }
  50% { box-shadow: 0 0 0 5px color-mix(in srgb, var(--primary, #2563eb) 16%, transparent), 0 2px 8px color-mix(in srgb, var(--primary, #2563eb) 45%, transparent); }
}

/* ---------- 返回顶部：圆环进度（JS 更新 --btd-p） ---------- */
.backtop {
  width: 46px;
  height: 46px;
  font-size: 17px;
  background: var(--card, #fff);
  color: var(--primary, #2563eb);
  border: 1px solid var(--line, #e8ebf1);
  box-shadow: 0 10px 26px rgba(20, 30, 60, .28);
}
.backtop::before {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  background:
    radial-gradient(circle, var(--card, #fff) 0 58%, transparent 59%),
    conic-gradient(var(--primary, #2563eb) calc(var(--btd-p, 0) * 1%), color-mix(in srgb, var(--line, #e8ebf1) 80%, transparent) 0);
}
.backtop .bt-arrow { position: relative; z-index: 1; }
.backtop:hover { transform: translateY(-3px); color: var(--primary, #2563eb); }

/* ---------- Hero 面板：网格纹理 + 光晕漂浮 ---------- */
.hero-panel {
  background-image:
    linear-gradient(135deg, color-mix(in srgb, var(--primary, #2563eb) 78%, #1e1b4b), color-mix(in srgb, var(--primary, #2563eb) 55%, #312e81)),
    radial-gradient(1200px 400px at 20% -20%, rgba(255, 255, 255, .28), transparent 60%);
  background-blend-mode: normal;
}
.hero-panel::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .06) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), rgba(0, 0, 0, .25) 70%, transparent);
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, .9), rgba(0, 0, 0, .25) 70%, transparent);
}
.hero-panel::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(600px 200px at 80% 0%, rgba(255, 255, 255, .14), transparent 65%);
}
.hero-orb-a { animation: orbDrift 9s ease-in-out infinite; }
.hero-orb-b { animation: orbDrift 12s ease-in-out infinite reverse; }
.hero-orb-c { animation: orbDrift 7s ease-in-out 1.2s infinite; }
@keyframes orbDrift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(-14px, 12px) scale(1.06); }
  66% { transform: translate(10px, -10px) scale(.96); }
}
.hero-stats .hs-item { position: relative; overflow: hidden; }
.hero-stats .hs-item::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 20%, rgba(255, 255, 255, .16), transparent 80%);
  transform: translateX(-110%);
  transition: transform .6s ease;
}
.hero-stats .hs-item:hover::after { transform: translateX(110%); }
.hero-stats .hs-item b { font-variant-numeric: tabular-nums; }
.hero-title { letter-spacing: 1px; }

/* ---------- 章节卡片：hover 光泽扫过 ---------- */
.chapter-grid .chapter-card { overflow: hidden; }
.chapter-grid .chapter-card::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0;
  left: -80%;
  width: 60%;
  pointer-events: none;
  background: linear-gradient(105deg, transparent, rgba(255, 255, 255, .55), transparent);
  transform: skewX(-18deg);
  transition: left .5s ease;
}
.chapter-grid .chapter-card:hover::after { left: 130%; }
html[data-theme="dark"] .chapter-grid .chapter-card::after {
  background: linear-gradient(105deg, transparent, rgba(255, 255, 255, .08), transparent);
}
/* 完成卡片微徽标 */
.chapter-grid .chapter-card.done::after { display: none; }
.chapter-grid .chapter-card.done:hover::before {
  color: color-mix(in srgb, var(--ok, #10b981) 26%, transparent);
}

/* ---------- 知识点卡片：hover 提亮 + 渐变描边 ---------- */
.point:hover { border-color: color-mix(in srgb, var(--primary, #2563eb) 34%, var(--line, #e8ebf1)); }
.point h4 { transition: color .16s ease; }
.point:hover h4 { color: var(--primary, #2563eb); }
html[data-theme="dark"] .point:hover h4 { color: color-mix(in srgb, var(--primary, #2563eb) 80%, #fff); }

/* ---------- 按钮：按压反馈 + 微光 ---------- */
.btn { position: relative; overflow: hidden; }
.btn::after {
  content: "";
  position: absolute;
  top: 0; bottom: 0;
  left: -70%;
  width: 45%;
  pointer-events: none;
  background: linear-gradient(105deg, transparent, rgba(255, 255, 255, .35), transparent);
  transform: skewX(-18deg);
  transition: left .45s ease;
}
.btn:hover::after { left: 130%; }
.btn:active { transform: scale(.97); }
html[data-theme="dark"] .btn::after { background: linear-gradient(105deg, transparent, rgba(255, 255, 255, .1), transparent); }

/* ---------- 选项：点击反馈 ---------- */
.option, .em-opt { transition: transform .1s ease, border-color .14s ease, background .14s ease, box-shadow .14s ease; }
.option:active, .em-opt:active { transform: scale(.985); }

/* ---------- 表格：hover 行 + 表头微调 ---------- */
table { border-collapse: separate; }
tbody tr { transition: background .12s ease; }
tbody tr:hover td { background: color-mix(in srgb, var(--primary-soft, #eff6ff) 70%, #fff) !important; }
html[data-theme="dark"] tbody tr:hover td { background: rgba(37, 99, 235, .16) !important; }
th { position: sticky; top: 0; z-index: 2; }

/* ---------- 搜索 / 目录 hover 微交互 ---------- */
.sr-item, .toc-list a, .crumbs a { position: relative; }
.sr-item { border-left: 3px solid transparent; }
.sr-item:hover { border-left-color: var(--primary, #2563eb); }

/* ---------- 页脚：渐变顶线 ---------- */
.site-footer { position: relative; }
.site-footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary, #2563eb), var(--accent, #7c3aed), var(--ok, #10b981));
  opacity: .5;
}

/* ---------- 全屏面板：标题装饰 ---------- */
.eo-head { position: relative; }
.eo-head::after {
  content: "";
  position: absolute;
  left: 20px; bottom: -1px;
  width: 46px; height: 3px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--primary, #2563eb), var(--accent, #7c3aed));
}

/* ---------- 模拟考选项点击光晕 ---------- */
.em-opt.sel { animation: emSel .18s ease; }
@keyframes emSel {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

/* ---------- 沉浸式阅读：内容最大宽度微调 ---------- */
.container { max-width: min(980px, 100%); }

/* ---------- 减少动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-orb-a, .hero-orb-b, .hero-orb-c, .brand::before,
  .chapter-grid .chapter-card::after, .btn::after,
  .hero-stats .hs-item::after, .em-opt.sel { animation: none !important; transition: none !important; }
}

/* =====================================================
   视觉升级 V3：滚动进入动画（Scroll Reveal）
   由 enhance.js 的 initReveal 观察视口并添加 .in
   ===================================================== */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .55s cubic-bezier(.2, .7, .2, 1), transform .55s cubic-bezier(.2, .7, .2, 1);
  will-change: opacity, transform;
}
.reveal[data-dir="left"] { transform: translateX(-26px); }
.reveal[data-dir="right"] { transform: translateX(26px); }
.reveal[data-dir="scale"] { transform: scale(.94); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none !important; transition: none !important; }
}