[hidden] { display: none !important; }

:root {
  --bg-1: #E8F4FF;
  --bg-2: #F8FCFF;
  --card: #FFFFFF;
  --text: #2C3E50;
  --text-2: #7A8B9E;
  --primary: #4FC3F7;
  --primary-2: #29B6F6;
  --primary-3: #03A9F4;
  --accent: #FFB6C1;
  --success: #4CAF50;
  --danger: #FF6B6B;
  --border: #E0EEF8;
  --shadow: 0 4px 20px rgba(79, 195, 247, 0.12);
  --shadow-hover: 0 8px 28px rgba(79, 195, 247, 0.22);
  --radius: 16px;
}
:root.dark {
  --bg-1: #1A1F2E;
  --bg-2: #0F1419;
  --card: #232A3D;
  --text: #E0E6F0;
  --text-2: #8B9BB4;
  --border: #2F3A52;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 8px 28px rgba(0, 0, 0, 0.45);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { min-height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 100%);
  background-attachment: fixed;
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background .3s, color .3s;
}

/* ===== 顶栏 ===== */
.topbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}
:root.dark .topbar { background: rgba(35, 42, 61, 0.7); }
.brand {
  font-size: 18px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}
.tabs {
  display: flex;
  gap: 4px;
  flex: 1;
  justify-content: center;
}
.tab {
  background: transparent;
  border: none;
  padding: 8px 18px;
  font-size: 15px;
  color: var(--text-2);
  cursor: pointer;
  border-radius: 10px;
  transition: all .2s;
  font-weight: 500;
}
.tab:hover { color: var(--primary-2); background: rgba(79, 195, 247, 0.08); }
.tab.active {
  color: white;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-2) 100%);
  box-shadow: 0 4px 12px rgba(79, 195, 247, 0.35);
}
.icon-btn {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 40px; height: 40px;
  font-size: 18px;
  cursor: pointer;
  transition: all .2s;
  display: flex; align-items: center; justify-content: center;
}
.icon-btn:hover { transform: scale(1.08); box-shadow: var(--shadow); }

/* ===== 主内容 ===== */
main {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 16px 80px;
}
.panel { display: none; animation: fadeIn .3s ease; }
.panel.active { display: block; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== 模式按钮 ===== */
.mode-bar {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.mode-btn {
  flex: 1;
  min-width: 120px;
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 600;
  background: var(--card);
  color: var(--text);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all .22s;
  box-shadow: var(--shadow);
}
.mode-btn:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  color: var(--primary-2);
}

/* ===== 进度条 ===== */
.progress-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 14px;
  color: var(--text-2);
}
.progress-track {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}
.progress-inner {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: 4px;
  transition: width .3s ease;
}

/* ===== 题目卡片 ===== */
.quiz-area { min-height: 200px; }
.q-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  animation: slideUp .3s ease;
  border: 1px solid var(--border);
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}
.q-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}
.q-type {
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 20px;
  font-weight: 600;
  letter-spacing: .5px;
}
.q-type-choice { background: rgba(79, 195, 247, 0.18); color: var(--primary-3); }
.q-type-fill { background: rgba(255, 182, 193, 0.25); color: #E91E63; }
.q-type-judge { background: rgba(255, 193, 7, 0.2); color: #F57C00; }
.q-cat {
  font-size: 12px;
  color: var(--text-2);
  background: var(--bg-1);
  padding: 4px 10px;
  border-radius: 12px;
}
:root.dark .q-cat { background: var(--border); }
.q-text {
  font-size: 17px;
  line-height: 1.7;
  margin-bottom: 20px;
  font-weight: 500;
}

/* ===== 选择题 ===== */
.q-options { display: flex; flex-direction: column; gap: 10px; }
.opt-btn {
  text-align: left;
  padding: 14px 18px;
  background: var(--bg-1);
  border: 2px solid transparent;
  border-radius: 12px;
  font-size: 15px;
  color: var(--text);
  cursor: pointer;
  transition: all .18s;
  font-family: inherit;
}
:root.dark .opt-btn { background: var(--border); }
.opt-btn:hover:not(.locked) {
  border-color: var(--primary);
  transform: translateX(4px);
  background: rgba(79, 195, 247, 0.08);
}
.opt-btn.correct { background: rgba(76, 175, 80, 0.15) !important; border-color: var(--success) !important; color: var(--success); font-weight: 600; }
.opt-btn.wrong { background: rgba(255, 107, 107, 0.15) !important; border-color: var(--danger) !important; color: var(--danger); font-weight: 600; }
.opt-btn.locked { cursor: default; }

/* ===== 填空题 ===== */
.q-fill { display: flex; gap: 10px; }
.fill-input {
  flex: 1;
  padding: 14px 18px;
  font-size: 16px;
  border: 2px solid var(--border);
  border-radius: 12px;
  background: var(--bg-1);
  color: var(--text);
  font-family: inherit;
  transition: all .18s;
}
:root.dark .fill-input { background: var(--border); }
.fill-input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(79, 195, 247, 0.15); }
.fill-input.correct { background: rgba(76, 175, 80, 0.1) !important; border-color: var(--success) !important; color: var(--success); font-weight: 600; }
.fill-input.wrong { background: rgba(255, 107, 107, 0.1) !important; border-color: var(--danger) !important; color: var(--danger); font-weight: 600; }

/* ===== 判断题 ===== */
.q-judge { display: flex; gap: 12px; }
.judge-btn {
  flex: 1;
  padding: 18px;
  font-size: 16px;
  font-weight: 600;
  background: var(--bg-1);
  border: 2px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  cursor: pointer;
  transition: all .18s;
  font-family: inherit;
}
:root.dark .judge-btn { background: var(--border); }
.judge-btn:hover { border-color: var(--primary); transform: translateY(-2px); }
.judge-btn.correct { background: rgba(76, 175, 80, 0.15) !important; border-color: var(--success) !important; color: var(--success); }
.judge-btn.wrong { background: rgba(255, 107, 107, 0.15) !important; border-color: var(--danger) !important; color: var(--danger); }

/* ===== 解析 ===== */
.q-explanation {
  margin-top: 18px;
  padding: 14px 16px;
  background: rgba(79, 195, 247, 0.08);
  border-left: 4px solid var(--primary);
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.7;
  animation: fadeIn .25s;
}
.q-explanation .ans { color: var(--primary-3); font-weight: 700; }
:root.dark .q-explanation .ans { color: var(--primary); }
.exp-note { color: var(--text-2); margin-top: 4px; font-size: 13px; }

/* ===== 操作按钮 ===== */
.quiz-actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
  justify-content: space-between;
}
button.primary, button.secondary, button.danger {
  padding: 12px 22px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: all .2s;
  font-family: inherit;
}
button.primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-2) 100%);
  color: white;
  box-shadow: 0 4px 14px rgba(79, 195, 247, 0.35);
}
button.primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(79, 195, 247, 0.5); }
button.secondary {
  background: var(--card);
  color: var(--text);
  border: 1px solid var(--border);
}
button.secondary:hover { border-color: var(--primary); color: var(--primary-2); }
button.danger {
  background: linear-gradient(135deg, #FF8A80 0%, var(--danger) 100%);
  color: white;
}
button.danger:hover { transform: translateY(-2px); }
button:disabled { opacity: .45; cursor: not-allowed; transform: none !important; }

/* ===== 搜索 ===== */
.search-box {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
}
.search-box input {
  flex: 1;
  padding: 14px 20px;
  font-size: 16px;
  border: 2px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  color: var(--text);
  font-family: inherit;
  transition: all .2s;
  box-shadow: var(--shadow);
}
.search-box input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(79, 195, 247, 0.15); }
.search-box button {
  padding: 0 24px;
  font-size: 20px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-2) 100%);
  color: white;
  border: none;
  border-radius: 14px;
  cursor: pointer;
  transition: all .2s;
}
.search-box button:hover { transform: scale(1.05); }
.search-hint { font-size: 13px; color: var(--text-2); margin-bottom: 16px; padding-left: 4px; }
.search-results { display: flex; flex-direction: column; gap: 10px; }
.search-card {
  background: var(--card);
  border-radius: 14px;
  padding: 16px 20px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: all .2s;
  animation: fadeIn .25s;
}
.search-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
.sc-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 6px; }
.sc-name { font-size: 16px; font-weight: 700; }
.sc-cat { font-size: 12px; color: var(--text-2); background: var(--bg-1); padding: 3px 10px; border-radius: 10px; }
:root.dark .sc-cat { background: var(--border); }
.sc-price {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-3);
  margin: 4px 0;
}
:root.dark .sc-price { color: var(--primary); }
.sc-spec, .sc-note { font-size: 13px; color: var(--text-2); }
mark { background: rgba(255, 193, 7, 0.4); color: inherit; padding: 0 2px; border-radius: 3px; }

/* ===== 统计 ===== */
.stat-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}
.stat-card {
  background: var(--card);
  border-radius: 14px;
  padding: 18px 12px;
  text-align: center;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.stat-card .num {
  font-size: 26px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-card .lbl { font-size: 13px; color: var(--text-2); margin-top: 2px; }
.stats-content h3 { margin: 20px 0 10px; font-size: 16px; color: var(--text); }
.stat-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-bottom: 12px;
  font-size: 14px;
}
.stat-table th, .stat-table td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--border); }
.stat-table th { background: var(--bg-1); font-weight: 600; color: var(--text-2); font-size: 13px; }
:root.dark .stat-table th { background: var(--border); }
.stat-table tr:last-child td { border-bottom: none; }
.stat-actions { display: flex; gap: 10px; margin-top: 24px; flex-wrap: wrap; }

/* ===== 空状态 ===== */
.empty-hint {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-2);
  font-size: 15px;
  line-height: 1.8;
}
.loading { text-align: center; padding: 30px; color: var(--text-2); }

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: rgba(44, 62, 80, 0.95);
  color: white;
  padding: 12px 24px;
  border-radius: 30px;
  font-size: 14px;
  opacity: 0;
  transition: all .3s;
  pointer-events: none;
  z-index: 9999;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}
:root.dark .toast { background: rgba(224, 230, 240, 0.95); color: #1A1F2E; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== 移动端 ===== */
@media (max-width: 640px) {
  .topbar { padding: 10px 12px; gap: 10px; }
  .brand { font-size: 15px; }
  .tab { padding: 7px 12px; font-size: 14px; }
  main { padding: 16px 12px 80px; }
  .mode-btn { padding: 12px; font-size: 14px; min-width: 0; }
  .q-card { padding: 18px; }
  .q-text { font-size: 16px; }
  .stat-card .num { font-size: 22px; }
}