:root {
  --bg: #fff7ed;
  --bg-grad: linear-gradient(180deg, #fff7ed 0%, #fff0e0 100%);
  --card: #ffffff;
  --soft: #fff7ed;
  --soft-warm: #fff3d6;
  --soft-sol: #fffdf5;
  --soft-bad: #fff0f0;
  --soft-ok: #eafaf1;
  --primary: #ff7a1a;
  --primary-d: #e85d00;
  --accent: #2bb673;
  --accent-d: #1f9b5e;
  --blue: #3b82f6;
  --ink: #2b2b2b;
  --ink-soft: #5b4636;
  --ink-sol: #8a6b3f;
  --muted: #8a8a8a;
  --line: #ffe3c7;
  --line-soft: #eeeeee;
  --warm-line: #f5c46b;
  --warm-ink: #b45309;
  --ok-ink: #17864b;
  --bad-ink: #c92a2a;
  --shadow: 0 8px 24px rgba(255, 122, 26, 0.18);
}

/* 深色模式：只覆盖语义变量，组件样式自动跟随 */
body.dark {
  --bg: #14161a;
  --bg-grad: linear-gradient(180deg, #14161a 0%, #0f1115 100%);
  --card: #1d2026;
  --soft: #23272e;
  --soft-warm: #2b2418;
  --soft-sol: #21252b;
  --soft-bad: #2c1d1d;
  --soft-ok: #16281e;
  --primary: #ff8c33;
  --primary-d: #ffa457;
  --accent: #34c98a;
  --accent-d: #2bb673;
  --blue: #60a5fa;
  --ink: #e8eaed;
  --ink-soft: #d3d7dd;
  --ink-sol: #c9b795;
  --muted: #9aa1ab;
  --line: #33383f;
  --line-soft: #2a2e35;
  --warm-line: #6b5326;
  --warm-ink: #e8b264;
  --ok-ink: #5fd99b;
  --bad-ink: #ff8080;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  background: var(--bg-grad);
  color: var(--ink);
  min-height: 100vh;
}

#app {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px 16px 40px;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* 顶部栏 */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.logo { font-size: 22px; font-weight: 800; color: var(--primary-d); }
.back-btn {
  background: var(--card); border: 2px solid var(--line); border-radius: 10px;
  padding: 6px 12px; font-size: 14px; font-weight: 700; color: var(--primary-d);
  cursor: pointer; margin-right: 8px;
}
.back-btn:hover { background: var(--soft); }
.topbar-right { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.sound-toggle {
  background: var(--card); border: 2px solid var(--line); border-radius: 50%;
  width: 34px; height: 34px; font-size: 16px; cursor: pointer;
  display: flex; align-items: center; justify-content: center; padding: 0;
  flex-shrink: 0;
}
.sound-toggle.off { opacity: 0.45; }
.best-record {
  font-size: 13px; color: var(--muted); white-space: nowrap;
  background: var(--card); padding: 6px 12px; border-radius: 999px;
  box-shadow: var(--shadow);
}

/* 视图切换 */
.view { display: none; flex: 1; animation: fade .25s ease; }
.view.active { display: flex; flex-direction: column; }
@keyframes fade { from { opacity: 0; transform: translateY(8px);} to {opacity:1;transform:none;} }

/* 主页 */
.hero { text-align: center; padding: 18px 0 8px; }
.hero h1 { font-size: 26px; color: var(--primary-d); }
.hero p { color: var(--muted); margin-top: 6px; font-size: 14px; }

.grade-pick { margin: 18px 0; }
.grade-pick label { font-size: 14px; color: var(--muted); display:block; margin-bottom: 8px; }
.grade-list { display: flex; flex-wrap: wrap; gap: 8px; }
.grade-chip {
  padding: 8px 14px; border-radius: 999px; border: 2px solid var(--line);
  background: var(--card); font-size: 14px; cursor: pointer; transition: .15s;
  color: var(--ink);
}
.grade-chip.active { background: var(--primary); color: #fff; border-color: var(--primary); }

.mode-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-top: 8px; }
.mode-card {
  background: var(--card); border: none; border-radius: 18px; padding: 18px 10px;
  box-shadow: var(--shadow); cursor: pointer; text-align: center; transition: .15s;
}
.mode-card:hover { transform: translateY(-4px); }
.mode-icon { font-size: 34px; }
.mode-title { font-weight: 700; margin-top: 6px; font-size: 16px; }
.mode-desc { font-size: 12px; color: var(--muted); margin-top: 2px; }

/* 设置 */
.view-title { font-size: 22px; color: var(--primary-d); margin: 12px 0 16px; }
.setup-card { background: var(--card); border-radius: 20px; padding: 20px; box-shadow: var(--shadow); }

/* 模拟卷 / 真题 */
.paper-list { display: flex; flex-direction: column; gap: 10px; }
.paper-item {
  text-align: left; width: 100%; background: var(--card); cursor: pointer;
  border: 2px solid var(--line); border-radius: 14px; padding: 12px 14px; transition: .15s;
}
.paper-item:hover { border-color: var(--primary); transform: translateY(-2px); }
.paper-item .pi-name { font-weight: 700; font-size: 15px; color: var(--ink); }
.paper-item .pi-sub { font-size: 12px; color: var(--muted); margin-top: 3px; }
.paper-tip { font-size: 12px; color: var(--muted); line-height: 1.6; margin-top: 4px; }

/* 水平自测诊断 */
.diag-bar {
  display: flex; align-items: center; gap: 10px; justify-content: space-between;
  background: var(--soft); border: 2px solid var(--warm-line); border-radius: 14px;
  padding: 10px 14px; margin-bottom: 12px;
}
.diag-text { font-size: 13px; color: var(--warm-ink); line-height: 1.5; flex: 1; }
.diag-text b { color: var(--primary-d); }
.diag-bar .mini-btn { flex-shrink: 0; }
.diag-tip {
  font-size: 13px; color: var(--warm-ink); background: var(--soft-warm);
  border-radius: 10px; padding: 8px 12px; margin-bottom: 12px;
}
.diag-tip b { color: var(--primary-d); }
.diag-result {
  background: var(--soft-ok); border: 2px solid var(--accent); border-radius: 14px;
  padding: 14px 16px; margin: 12px 0;
}
.dr-title { font-weight: 800; font-size: 16px; color: var(--ok-ink); }
.dr-sub { font-size: 13px; color: var(--muted); line-height: 1.6; margin-top: 6px; }
.paper-meta { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.ps-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 10px 0; border-bottom: 1px dashed var(--line); font-size: 15px;
}
.ps-row:last-child { border-bottom: none; }
.ps-row b { color: var(--primary-d); }
.setup-row { margin-bottom: 20px; }
.setup-label { font-weight: 700; display: block; margin-bottom: 10px; }
.op-check { display: flex; flex-wrap: wrap; gap: 10px; }
.op-check label {
  display: flex; align-items: center; gap: 6px; padding: 8px 14px;
  border: 2px solid var(--line); border-radius: 12px; cursor: pointer; font-size: 15px;
}
.op-check input { accent-color: var(--primary); width: 16px; height: 16px; }

.seg { display: flex; gap: 8px; flex-wrap: wrap; }
.seg button {
  padding: 8px 16px; border-radius: 12px; border: 2px solid var(--line);
  background: var(--card); cursor: pointer; font-size: 14px; color: var(--ink);
}
.seg button.active { background: var(--accent); color: #fff; border-color: var(--accent); }

.btn-primary {
  background: var(--primary); color: #fff; border: none; border-radius: 14px;
  padding: 12px 20px; font-size: 16px; font-weight: 700; cursor: pointer; transition: .15s;
  box-shadow: var(--shadow);
}
.btn-primary:hover { background: var(--primary-d); }
.btn-primary.big { width: 100%; margin-top: 4px; padding: 14px; font-size: 18px; }
.btn-ghost {
  background: var(--card); color: var(--primary-d); border: 2px solid var(--line);
  border-radius: 14px; padding: 12px 20px; font-size: 16px; font-weight: 700; cursor: pointer;
}

/* 练习 */
.practice-top { margin-bottom: 16px; }
.progress-wrap { height: 12px; background: var(--line); border-radius: 999px; overflow: hidden; }
.progress-bar { height: 100%; width: 0%; background: linear-gradient(90deg, var(--primary), #ffb347); transition: .25s; }
.practice-meta { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; margin-top: 10px; font-weight: 700; }
.fav-btn {
  border: 2px solid var(--line); background: var(--card); border-radius: 12px; padding: 4px 10px;
  font-size: 13px; font-weight: 700; color: var(--primary-d); cursor: pointer; transition: .15s;
}
.fav-btn:hover { border-color: #f5a623; background: var(--soft); }
.fav-btn.on { border-color: #f5a623; background: var(--soft-warm); color: #d98200; }
.timer { color: var(--blue); }
.live-score { color: #f5a623; }

/* 解析面板 */
.solution-box {
  margin: 12px auto 0; max-width: 420px; padding: 12px 14px; text-align: left;
  background: var(--soft-sol); border: 2px dashed var(--warm-line); border-radius: 14px;
}
.sol-title { font-weight: 800; color: var(--primary-d); margin-bottom: 6px; font-size: 15px; }
.sol-step { font-size: 15px; line-height: 1.65; color: var(--ink-soft); }
.sol-mini { margin-top: 6px; font-size: 13px; line-height: 1.55; color: var(--ink-sol); background: var(--soft-warm); border-radius: 8px; padding: 6px 8px; }

.question-stage {
  background: var(--card); border-radius: 22px; padding: 30px 20px; text-align: center;
  box-shadow: var(--shadow); flex: 1; display: flex; flex-direction: column; justify-content: center;
}
.question { font-size: 44px; font-weight: 800; color: var(--ink); letter-spacing: 2px; }
.answer-input {
  margin: 22px auto 0; width: 88%; max-width: 360px; font-size: 26px; text-align: center;
  padding: 12px; border: 3px solid var(--line); border-radius: 16px; outline: none; color: var(--primary-d); background: var(--card);
}
.answer-input:focus { border-color: var(--primary); }
.choice-box { display: flex; flex-direction: column; gap: 10px; margin-top: 18px; }
/* 判断题：两个选项并排、大号点选 */
.choice-box.judge { flex-direction: row; gap: 14px; margin-top: 26px; }
.choice-opt {
  padding: 14px 16px; border: 2px solid var(--line); border-radius: 14px; background: var(--card);
  font-size: 18px; cursor: pointer; text-align: left; transition: .15s; color: var(--ink);
}
.choice-opt:hover { border-color: var(--primary); background: var(--soft); }
.choice-opt.judge-opt {
  flex: 1; padding: 22px 10px; font-size: 24px; font-weight: 800; text-align: center;
  letter-spacing: 2px; color: var(--primary-d);
}
.choice-opt.correct { border-color: var(--accent); background: var(--soft-ok); color: var(--ok-ink); }
.choice-opt.wrong { border-color: var(--bad-ink); background: var(--soft-bad); color: var(--bad-ink); }
/* 多选题选项 */
.choice-hint { font-size: 14px; color: #f5a623; font-weight: 700; margin: 2px 0 4px; text-align: center; }
.choice-multi-opt { display: flex; align-items: center; gap: 10px; }
.choice-multi-opt::before {
  content: ""; width: 20px; height: 20px; flex: 0 0 auto; border: 2px solid var(--line);
  border-radius: 6px; background: var(--card); transition: .12s;
}
.choice-multi-opt.selected { border-color: var(--primary); background: var(--soft); }
.choice-multi-opt.selected::before { background: var(--primary); border-color: var(--primary); box-shadow: inset 0 0 0 4px var(--card); }

/* 填空题符号快捷栏 */
.symbol-bar {
  display: flex; gap: 8px; margin: 12px auto 0; padding: 6px 4px 10px;
  max-width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;
  justify-content: flex-start; scrollbar-width: none;
}
.symbol-bar::-webkit-scrollbar { display: none; }
.symbol-key {
  flex: 0 0 auto; min-width: 42px; height: 42px; padding: 0 10px;
  border: 2px solid var(--line); border-radius: 12px; background: var(--card);
  font-size: 19px; font-weight: 700; color: var(--primary-d); cursor: pointer;
  transition: .12s; user-select: none; -webkit-user-select: none; -webkit-tap-highlight-color: transparent;
}
.symbol-key:hover { border-color: var(--primary); background: var(--soft); }
.symbol-key:active { transform: scale(.93); background: var(--soft); }
.feedback { min-height: 28px; margin-top: 14px; font-size: 18px; font-weight: 700; }
.feedback.right { color: var(--accent); }
.feedback.wrong { color: var(--bad-ink); }
.practice-btns { display: flex; gap: 12px; justify-content: center; margin-top: 18px; }

/* 结果 */
.result-card { background: var(--card); border-radius: 22px; padding: 26px 20px; box-shadow: var(--shadow); text-align: center; }
.result-emoji { font-size: 56px; }
.result-card h2 { color: var(--primary-d); margin: 6px 0 18px; }
.result-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.stat { background: var(--soft); border-radius: 14px; padding: 12px 4px; }
.stat-num { font-size: 24px; font-weight: 800; color: var(--primary-d); }
.stat-label { font-size: 12px; color: var(--muted); margin-top: 2px; }
.stars-line { font-size: 30px; margin: 16px 0; min-height: 36px; }
.wrong-review { text-align: left; margin: 14px 0; max-height: 220px; overflow-y: auto; }
.wrong-item { background: var(--soft-bad); border-radius: 12px; padding: 10px 14px; margin-bottom: 8px; font-size: 16px; }
.wrong-item b { color: var(--bad-ink); }
.result-btns { display: flex; gap: 12px; justify-content: center; margin-top: 14px; }

/* 错题本 */
.wrong-list { flex: 1; overflow-y: auto; margin-bottom: 16px; }
.wrong-empty { text-align: center; color: var(--muted); padding: 40px 0; }
.wl-item { background: var(--card); border-radius: 14px; padding: 12px 16px; margin-bottom: 10px; box-shadow: var(--shadow); display:flex; justify-content: space-between; align-items:center; }
.wl-item .wl-q { font-size: 18px; font-weight: 700; }
.wl-item .wl-a { color: var(--bad-ink); font-size: 14px; }
.wl-del {
  background: none; border: none; color: var(--muted); cursor: pointer;
  padding: 6px; display: inline-flex; align-items: center; justify-content: center;
  transition: color .18s ease;
}
.wl-del:hover { color: var(--bad-ink); }
.wl-del .trash-ico { display: block; width: 20px; height: 20px; }
.wl-del .trash-lid {
  transform-box: view-box;
  transform-origin: 21px 7px;
  transition: transform .22s cubic-bezier(.34, 1.56, .64, 1);
}
.wl-del:hover .trash-lid { transform: rotate(-38deg); }

/* 错题本增强 */
.wrong-filters { padding: 12px 14px; margin-bottom: 10px; }
.wrong-filters .setup-row { margin: 6px 0; }
.wl-block { display: block; }
.wl-head { display: flex; justify-content: space-between; align-items: flex-start; }
.wl-kp { font-size: 12px; color: var(--muted); margin-top: 4px; }
.due-tag {
  display: inline-block; margin-left: 6px; padding: 1px 7px; font-size: 12px; font-weight: 700;
  color: var(--warm-ink); background: var(--soft-warm); border-radius: 8px; vertical-align: middle;
}
.reason-row { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.reason-chip {
  padding: 4px 10px; font-size: 12px; border-radius: 999px; border: 1.5px solid var(--line);
  background: var(--card); color: var(--muted); cursor: pointer; transition: .12s;
}
.reason-chip.on { background: var(--soft-bad); border-color: var(--bad-ink); color: var(--bad-ink); font-weight: 700; }
.wl-acts { display: flex; gap: 8px; justify-content: flex-end; align-items: center; margin-top: 8px; }
.mini-btn {
  padding: 5px 12px; font-size: 13px; font-weight: 700; border-radius: 10px;
  border: 2px solid var(--line); background: var(--card); color: var(--accent); cursor: pointer;
}
.mini-btn:hover { border-color: var(--accent); background: var(--soft-ok); }
.due-bar {
  display: flex; justify-content: space-between; align-items: center; gap: 10px;
  background: var(--soft); border: 2px solid var(--warm-line); border-radius: 14px;
  padding: 10px 14px; margin-bottom: 10px; font-size: 14px; font-weight: 700; color: var(--warm-ink);
}

/* 学习仪表盘 */
.dash-card { background: var(--card); border-radius: 20px; padding: 16px; box-shadow: var(--shadow); margin-top: 16px; }
.dash-title { font-weight: 800; color: var(--primary-d); margin-bottom: 10px; }
.dash-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.dash-mods { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.mod-chip { font-size: 12px; padding: 3px 9px; border-radius: 999px; background: var(--soft); color: var(--primary-d); }
.mod-chip b { font-weight: 800; }
.dash-stat { background: var(--soft); border-radius: 12px; padding: 10px 4px; text-align: center; }
.ds-num { font-size: 20px; font-weight: 800; color: var(--primary-d); }
.ds-label { font-size: 11px; color: var(--muted); margin-top: 2px; }
.heatmap { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; margin-top: 12px; }
.heat-cell { border-radius: 8px; padding: 6px 6px; font-size: 11px; line-height: 1.35; color: #fff; background: var(--line); }
.heat-cell b { display: block; font-size: 12px; }
.heat-empty { grid-column: 1 / -1; font-size: 12px; color: var(--muted); text-align: center; padding: 8px 0; }
.dash-btns { display: flex; gap: 8px; margin-top: 12px; }
.dash-btns .mini-btn { flex: 1; text-align: center; }

/* 报告 / 回看 */
.report-card { background: var(--card); border-radius: 20px; padding: 20px; box-shadow: var(--shadow); flex: 1; overflow-y: auto; }
.report-body { font-size: 15px; line-height: 1.8; color: var(--ink); }
.report-body h3 { font-size: 16px; color: var(--primary-d); margin: 14px 0 6px; }
.report-body h3:first-child { margin-top: 0; }
.report-body .rp-row { display: flex; justify-content: space-between; padding: 4px 0; border-bottom: 1px dashed var(--line-soft); }
.report-body .rp-weak { color: var(--bad-ink); font-weight: 700; }
.report-body .rp-good { color: var(--ok-ink); font-weight: 700; }
.report-body .rp-tip { background: var(--soft-sol); border-left: 4px solid var(--warm-line); padding: 8px 10px; border-radius: 8px; margin-top: 8px; }
.session-item { border-bottom: 1px dashed var(--line-soft); padding: 10px 0; }
.session-item .si-q { font-weight: 700; }
.session-item .si-a { font-size: 13px; color: var(--muted); margin-top: 2px; }
.session-item .si-r { font-weight: 700; }
.session-item .si-r.ok { color: var(--ok-ink); }
.session-item .si-r.no { color: var(--bad-ink); }

/* 知识点讲义 */
.lecture-card {
  background: var(--card); border-radius: 20px; padding: 22px 20px; box-shadow: var(--shadow);
  flex: 1; border-left: 6px solid var(--primary);
}
.lecture-page {
  display: inline-block; font-size: 13px; font-weight: 700; color: var(--warm-ink);
  background: var(--soft-warm); border-radius: 8px; padding: 2px 10px; margin-bottom: 12px;
}
.lecture-body { font-size: 17px; line-height: 1.9; color: var(--ink); }
.kp-link {
  display: inline-block; margin-top: 6px; padding: 2px 8px; font-size: 12px;
  border: 1px solid var(--line); border-radius: 8px; background: var(--card);
  color: var(--primary-d); cursor: pointer;
}
.kp-link:hover { border-color: var(--primary); background: var(--soft); }
.kp-link:disabled { opacity: .5; cursor: default; }
.sol-kp { margin-top: 10px; }

/* 打印 / 导出 PDF */
.print-area { display: none; }
@media print {
  /* 打印一律用浅色，避免深色模式下黑底黑字 */
  body, body.dark { background: #fff !important; }
  body.printing #app { display: none !important; }
  body.printing .print-area { display: block !important; }
  .print-area { color: #000; font-family: system-ui, "Microsoft YaHei", sans-serif; }
  .print-area h1 { font-size: 20px; margin: 0 0 6px; }
  .print-area .pr-meta { font-size: 12px; color: #555; margin-bottom: 14px; }
  .print-area .pr-item { border-bottom: 1px dashed #bbb; padding: 10px 0; page-break-inside: avoid; }
  .print-area .pr-q { font-size: 15px; font-weight: 700; margin-bottom: 4px; }
  .print-area .pr-row { font-size: 13px; margin-bottom: 3px; }
  .print-area .pr-sol { font-size: 12px; color: #333; }
  .print-area .pr-space { height: 46px; }
  @page { margin: 14mm; }
}

.foot { text-align: center; color: var(--muted); font-size: 12px; margin-top: 18px; }

@media (max-width: 480px) {
  .question { font-size: 36px; }
  .answer-input { font-size: 26px; }
  .result-stats { grid-template-columns: repeat(2, 1fr); }
  .mode-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .mode-card { padding: 14px 8px; }
  .mode-icon { font-size: 28px; }
  .mode-title { font-size: 15px; }
  /* 七个章节 chip 在窄屏收紧，避免占太多行 */
  .grade-list { gap: 6px; }
  .grade-chip { padding: 7px 11px; font-size: 13px; }
  /* 顶栏在窄屏收紧：返回键 + 两个圆钮会挤，先让位给功能按钮 */
  .logo { font-size: 18px; }
  .topbar-right { gap: 6px; }
  .sound-toggle { width: 30px; height: 30px; font-size: 15px; }
  .best-record { display: none; }
}