/* ========== 全局 ========== */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --primary: #4f7cff;
  --primary-light: #e8efff;
  --success: #34b37e;
  --danger: #ef5b5b;
  --warning: #f5a623;
  --text: #2b3245;
  --text-light: #8a93a8;
  --border: rgba(79, 124, 255, 0.14);
  --radius: 16px;
  --shadow: 0 8px 30px rgba(79, 124, 255, 0.08);
}

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 15% 20%, rgba(79,124,255,0.07), transparent 40%),
    radial-gradient(circle at 85% 10%, rgba(155,109,255,0.06), transparent 40%),
    radial-gradient(circle at 50% 90%, rgba(52,179,126,0.05), transparent 40%),
    #fafbff;
  min-height: 100vh;
}

.hidden { display: none !important; }

/* 毛玻璃卡片 */
.glass {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(14px) saturate(1.2);
  -webkit-backdrop-filter: blur(14px) saturate(1.2);
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.container { max-width: 1080px; margin: 0 auto; padding: 24px 18px 60px; }

/* ========== 头部 ========== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  border-radius: 0 0 var(--radius) var(--radius);
  border-top: none;
}
.header-inner {
  max-width: 1080px; margin: 0 auto; padding: 14px 18px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark {
  width: 46px; height: 46px; border-radius: 12px;
  background: linear-gradient(135deg, #4f7cff, #9b6dff);
  color: #fff; font-size: 26px; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 6px 16px rgba(79,124,255,0.35);
}
.logo h1 { font-size: 18px; letter-spacing: 0.5px; }
.logo p { font-size: 12px; color: var(--text-light); margin-top: 2px; }

.tabs { display: flex; gap: 6px; flex-wrap: wrap; }
.tab {
  border: none; cursor: pointer; font-size: 14px; padding: 9px 16px;
  border-radius: 999px; background: transparent; color: var(--text);
  transition: all 0.2s ease;
}
.tab:hover { background: var(--primary-light); color: var(--primary); }
.tab.active {
  background: linear-gradient(135deg, #4f7cff, #7a9bff);
  color: #fff; box-shadow: 0 4px 12px rgba(79,124,255,0.35);
}

/* ========== 通用 ========== */
.view-title { margin: 26px 4px 18px; }
.view-title h2 { font-size: 22px; margin-bottom: 6px; }
.view-title p { font-size: 13px; color: var(--text-light); }

button.btn {
  border: none; cursor: pointer; font-size: 14px; padding: 10px 20px;
  border-radius: 10px; background: linear-gradient(135deg, #4f7cff, #7a9bff);
  color: #fff; transition: all 0.2s ease; box-shadow: 0 4px 12px rgba(79,124,255,0.25);
}
button.btn:hover { transform: translateY(-1px); box-shadow: 0 6px 16px rgba(79,124,255,0.35); }
button.btn.ghost {
  background: var(--primary-light); color: var(--primary); box-shadow: none;
  border: 1px solid var(--border);
}
button.btn.ghost:hover { background: #dbe7ff; }
button.btn.small { padding: 6px 12px; font-size: 13px; border-radius: 8px; }

.placeholder { text-align: center; color: var(--text-light); padding: 80px 20px; font-size: 15px; }

.badge {
  display: inline-block; font-size: 12px; padding: 3px 10px; border-radius: 999px;
  background: var(--primary-light); color: var(--primary);
}
.badge.done { background: rgba(52,179,126,0.12); color: var(--success); }
.badge.warn { background: rgba(245,166,35,0.14); color: var(--warning); }

/* ========== 学习路径 ========== */
.chapter-card { padding: 22px 24px; margin-bottom: 20px; }
.chapter-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.chapter-head h3 { font-size: 18px; display: flex; align-items: center; gap: 10px; }
.chapter-num {
  width: 30px; height: 30px; border-radius: 8px; font-size: 14px;
  background: linear-gradient(135deg, #4f7cff, #9b6dff); color: #fff;
  display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.chapter-bar { flex: 1 1 160px; max-width: 260px; height: 8px; border-radius: 99px; background: #edf1f8; overflow: hidden; }
.chapter-bar-fill { height: 100%; border-radius: 99px; background: linear-gradient(90deg, #4f7cff, #34b37e); transition: width 0.4s ease; }
.chapter-bar-label { font-size: 12px; color: var(--text-light); margin-left: 8px; white-space: nowrap; }

.section-list { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.section-item {
  display: flex; align-items: center; gap: 12px; padding: 12px 14px;
  border-radius: 12px; border: 1px solid transparent; cursor: pointer;
  transition: all 0.15s ease;
}
.section-item:hover { background: rgba(79,124,255,0.05); border-color: var(--border); }
.section-item .check {
  width: 22px; height: 22px; border-radius: 50%; border: 2px solid #cdd6e8; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center; font-size: 13px; color: #fff;
  transition: all 0.2s ease;
}
.section-item.done .check { background: var(--success); border-color: var(--success); }
.section-item .sec-title { flex: 1; font-size: 14px; }
.section-item.done .sec-title { color: var(--text-light); text-decoration: line-through; text-decoration-color: rgba(52,179,126,0.5); }
.section-item .sec-time { font-size: 12px; color: var(--text-light); white-space: nowrap; }
.section-item .go { font-size: 12px; color: var(--primary); white-space: nowrap; }

/* ========== 讲义 ========== */
.lecture-layout { display: grid; grid-template-columns: 260px 1fr; gap: 18px; align-items: start; }
.lecture-nav { padding: 16px; position: sticky; top: 100px; max-height: calc(100vh - 130px); overflow-y: auto; }
.lecture-nav h4 { font-size: 14px; margin: 10px 4px 8px; color: var(--text-light); font-weight: 600; }
.nav-sec {
  display: block; width: 100%; text-align: left; border: none; background: transparent;
  padding: 9px 12px; border-radius: 10px; font-size: 13px; color: var(--text); cursor: pointer;
  transition: background 0.15s ease; margin-bottom: 2px;
}
.nav-sec:hover { background: var(--primary-light); }
.nav-sec.active { background: linear-gradient(135deg, #4f7cff, #7a9bff); color: #fff; }
.nav-sec .dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: #cdd6e8; margin-right: 7px; vertical-align: middle; }
.nav-sec.done .dot { background: var(--success); }
.nav-sec.active .dot { background: #fff; }

.lecture-content { padding: 30px 34px; min-height: 400px; }
.lecture-content h2 { font-size: 20px; margin-bottom: 4px; }
.lecture-meta { font-size: 12px; color: var(--text-light); margin-bottom: 18px; }
.lecture-body { font-size: 15px; line-height: 1.9; }
.lecture-body p { margin: 12px 0; }
.lecture-body h3 { font-size: 16px; margin: 26px 0 8px; padding-left: 10px; border-left: 4px solid var(--primary); }
.lecture-body ul, .lecture-body ol { padding-left: 24px; margin: 10px 0; }
.lecture-body li { margin: 6px 0; }

.example {
  margin: 18px 0; padding: 16px 18px; border-radius: 12px;
  background: rgba(79,124,255,0.05); border: 1px solid var(--border);
}
.example-title { font-weight: 700; font-size: 14px; color: var(--primary); margin-bottom: 8px; }
.solution-title { font-weight: 700; font-size: 14px; color: var(--success); margin: 14px 0 6px; }
.key-box {
  margin: 16px 0; padding: 14px 18px; border-radius: 12px;
  background: rgba(52,179,126,0.07); border: 1px solid rgba(52,179,126,0.25);
}
.key-box strong { color: var(--success); }
.tip-box {
  margin: 16px 0; padding: 14px 18px; border-radius: 12px;
  background: rgba(245,166,35,0.08); border: 1px solid rgba(245,166,35,0.3);
}
.tip-box strong { color: #c47f0e; }

.lecture-actions { display: flex; gap: 10px; margin-top: 28px; padding-top: 20px; border-top: 1px dashed var(--border); }

/* ========== 测试 ========== */
.test-toolbar { padding: 16px 18px; margin-bottom: 18px; display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.test-toolbar .label { font-size: 14px; font-weight: 600; }
.chip {
  border: 1px solid var(--border); background: #fff; color: var(--text);
  padding: 8px 18px; border-radius: 999px; cursor: pointer; font-size: 14px; transition: all 0.15s ease;
}
.chip:hover { border-color: var(--primary); color: var(--primary); }
.chip.active { background: linear-gradient(135deg, #4f7cff, #7a9bff); color: #fff; border-color: transparent; }
.test-history { margin-left: auto; font-size: 13px; color: var(--text-light); }

.question-card { padding: 22px 24px; margin-bottom: 16px; }
.q-head { display: flex; gap: 10px; align-items: baseline; margin-bottom: 12px; }
.q-num { font-weight: 700; color: var(--primary); font-size: 14px; white-space: nowrap; }
.q-text { font-size: 15px; line-height: 1.8; }
.q-options { display: flex; flex-direction: column; gap: 8px; margin-top: 6px; }
.q-option {
  display: flex; align-items: flex-start; gap: 10px; padding: 10px 14px;
  border-radius: 10px; border: 1px solid #e5eaf3; cursor: pointer; font-size: 14px;
  transition: all 0.15s ease; line-height: 1.7;
}
.q-option:hover { border-color: var(--primary); background: rgba(79,124,255,0.04); }
.q-option input { margin-top: 5px; accent-color: var(--primary); }
.q-option.correct { border-color: var(--success); background: rgba(52,179,126,0.08); }
.q-option.wrong { border-color: var(--danger); background: rgba(239,91,91,0.08); }
.q-option.disabled { pointer-events: none; opacity: 0.85; }

.q-explain {
  margin-top: 14px; padding: 14px 16px; border-radius: 10px; font-size: 14px; line-height: 1.8;
  background: rgba(79,124,255,0.05); border-left: 4px solid var(--primary);
}
.q-explain.good { border-left-color: var(--success); background: rgba(52,179,126,0.07); }
.q-explain.bad { border-left-color: var(--danger); background: rgba(239,91,91,0.07); }
.q-verdict { font-weight: 700; margin-bottom: 6px; }
.q-verdict.good { color: var(--success); }
.q-verdict.bad { color: var(--danger); }

.test-result { padding: 24px; margin-bottom: 18px; text-align: center; }
.test-result .score { font-size: 40px; font-weight: 800; background: linear-gradient(135deg, #4f7cff, #9b6dff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.test-result .score-sub { color: var(--text-light); font-size: 14px; margin-top: 4px; }

/* ========== 进度 ========== */
.progress-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 18px; margin-bottom: 20px; }
.stat-card { padding: 20px 22px; }
.stat-card h4 { font-size: 15px; margin-bottom: 14px; display: flex; justify-content: space-between; align-items: center; }
.stat-card h4 .val { color: var(--primary); font-size: 18px; }
.stat-card h4 .val.green { color: var(--success); }
.pbar { height: 10px; border-radius: 99px; background: #edf1f8; overflow: hidden; margin: 8px 0 4px; }
.pbar-fill { height: 100%; border-radius: 99px; background: linear-gradient(90deg, #4f7cff, #34b37e); transition: width 0.4s ease; }
.pbar-row { display: flex; justify-content: space-between; font-size: 13px; color: var(--text-light); }

.cal-card { padding: 20px 22px; grid-column: 1 / -1; }
.cal-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; flex-wrap: wrap; gap: 10px; }
.cal-head h4 { font-size: 15px; }
.cal-month { font-weight: 700; font-size: 15px; }
.cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; }
.cal-weekday { text-align: center; font-size: 12px; color: var(--text-light); padding: 4px 0; }
.cal-day {
  aspect-ratio: 1; border-radius: 10px; display: flex; align-items: center; justify-content: center;
  font-size: 13px; color: var(--text); border: 1px solid transparent; transition: all 0.15s ease;
}
.cal-day.empty { visibility: hidden; }
.cal-day.today { border-color: var(--primary); color: var(--primary); font-weight: 700; }
.cal-day.checked { background: linear-gradient(135deg, #4f7cff, #34b37e); color: #fff; cursor: pointer; }
.cal-day:not(.empty):not(.checked) { cursor: pointer; }
.cal-day:not(.empty):not(.checked):hover { background: var(--primary-light); }
.cal-legend { font-size: 12px; color: var(--text-light); margin-top: 12px; }

.data-actions { padding: 20px 22px; display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.data-actions .note { font-size: 13px; color: var(--text-light); flex-basis: 100%; }

.wrong-card { padding: 20px 24px; margin-bottom: 14px; }
.wrong-card .wrong-head { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; margin-bottom: 8px; flex-wrap: wrap; }
.empty-hint { text-align: center; padding: 30px; color: var(--text-light); font-size: 14px; }

/* ========== 响应式 ========== */
@media (max-width: 820px) {
  .lecture-layout { grid-template-columns: 1fr; }
  .lecture-nav { position: static; max-height: none; }
  .lecture-content { padding: 22px 18px; }
  .logo h1 { font-size: 15px; }
  .logo-mark { width: 38px; height: 38px; font-size: 22px; }
  .tab { padding: 8px 12px; font-size: 13px; }
  .header-inner { padding: 12px 14px; }
}