/* styles.css — 移动端布局（360–430 CSS 像素，触控目标 ≥44px，深浅色） */
:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --line: #e4e6eb;
  --text: #1f2329;
  --muted: #8a919f;
  --primary: #2f6fed;
  --primary-weak: #e8f0fe;
  --green: #1f9e64;
  --green-weak: #e6f6ee;
  --green-line: #bfe6d1;
  --red: #d73a49;
  --red-weak: #fdecee;
  --red-line: #f5c2c8;
  --orange: #d97706;
  --orange-weak: #fdf3e3;
  --orange-line: #f0d9ac;
  --amber: #b45309;
  --safe-b: env(safe-area-inset-bottom, 0px);
  --safe-t: env(safe-area-inset-top, 0px);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121417;
    --card: #1d2025;
    --line: #2e3239;
    --text: #e8eaed;
    --muted: #9aa0aa;
    --primary: #5b8def;
    --primary-weak: #22314d;
    --green: #3bb077;
    --green-weak: #173226;
    --green-line: #2b5541;
    --red: #f0626f;
    --red-weak: #3a1d21;
    --red-line: #5c2b30;
    --orange: #e8a23d;
    --orange-weak: #3a2d14;
    --orange-line: #5c4a1f;
    --amber: #f0b95b;
  }
}
* { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }
html { font-size: 18px; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  background: var(--bg); color: var(--text);
  padding-top: var(--safe-t);
  line-height: 1.6;
  min-height: 100vh;
}

/* ===================== 顶部 ===================== */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: var(--card); border-bottom: 1px solid var(--line);
  padding: 10px 16px;
  display: flex; align-items: center; justify-content: space-between;
}
.topbar h1 { font-size: 1rem; font-weight: 700; }
.topbar .sub { font-size: .72rem; color: var(--muted); }

/* ===================== 主内容 ===================== */
main { max-width: 520px; margin: 0 auto; padding: 12px 12px calc(72px + var(--safe-b)); }
.view { display: none; }
.view.active { display: block; }

/* ===================== 卡片 ===================== */
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 14px; margin-bottom: 12px;
}
.card h2 { font-size: .95rem; margin-bottom: 8px; }
.note { font-size: .8rem; color: var(--muted); }
.hint { font-size: .8rem; color: var(--muted); margin-top: 6px; }
.empty { padding: 28px 10px; text-align: center; color: var(--muted); font-size: .9rem; }

/* ===================== 今日 ===================== */
.today-stats { display: flex; gap: 10px; }
.today-stat {
  flex: 1; background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 14px 8px; text-align: center;
}
.today-stat .num { font-size: 1.6rem; font-weight: 800; color: var(--primary); }
.today-stat .cap { font-size: .75rem; color: var(--muted); margin-top: 2px; }
.batch-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-top: 8px; }
.batch-row .lbl { font-size: .8rem; color: var(--muted); }
.radios { display: flex; gap: 4px; }
.radios label {
  display: inline-flex; align-items: center; gap: 4px;
  border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px;
  font-size: .85rem; min-height: 44px;
}
.radios input { accent-color: var(--primary); }
.pending-link {
  display: block; margin-top: 10px; text-align: center;
  color: var(--amber); font-size: .85rem; background: none; border: none;
  min-height: 44px; width: 100%;
}

/* ===================== 按钮 ===================== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 46px; padding: 10px 18px;
  border: 1px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text);
  font-size: .92rem; font-weight: 600;
  cursor: pointer; width: 100%;
}
.btn + .btn { margin-top: 8px; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn.danger { background: var(--red); border-color: var(--red); color: #fff; }
.btn.sm { min-height: 40px; padding: 6px 12px; font-size: .82rem; width: auto; }
.btn.sm + .btn.sm { margin-top: 0; margin-left: 8px; }
.btn:disabled { opacity: .45; }
.btn.on { background: var(--primary-weak); border-color: var(--primary); color: var(--primary); }

/* ===================== 练习页 ===================== */
.prac-head {
  display: flex; align-items: center; gap: 10px; margin-bottom: 10px;
}
.prac-head .mode { font-size: .75rem; color: var(--muted); background: var(--card); border: 1px solid var(--line); border-radius: 999px; padding: 4px 10px; }
.prac-head .pos { flex: 1; text-align: right; font-size: .9rem; font-weight: 700; }
.filter-btn {
  min-height: 44px; padding: 0 16px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text); font-size: .88rem; cursor: pointer;
}

.qmeta { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 10px; }
.tag {
  font-size: .72rem; color: var(--muted);
  background: var(--bg); border: 1px solid var(--line); border-radius: 999px;
  padding: 2px 8px; line-height: 1.5;
}
.tag.id { color: var(--primary); background: var(--primary-weak); border-color: var(--primary); }
.tag.type { color: var(--orange); background: var(--orange-weak); border-color: var(--orange-line); }
.tag.pending { color: #fff; background: var(--red); border-color: var(--red); font-weight: 700; }
.tag.unreviewed { color: var(--amber); background: var(--orange-weak); border-color: var(--orange-line); }
.tag.src { max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tag.fav { color: var(--orange); }

.pendwarn {
  background: var(--red-weak); border: 1px solid var(--red-line); color: var(--red);
  border-radius: 10px; padding: 10px 12px; font-size: .82rem; margin-bottom: 10px;
}
.pendnote {
  background: var(--orange-weak); border: 1px solid var(--orange-line); color: var(--amber);
  border-radius: 10px; padding: 8px 12px; font-size: .78rem; margin-bottom: 10px;
}
.stem { font-size: 1rem; line-height: 1.7; margin-bottom: 14px; font-weight: 500; }

.opts { display: flex; flex-direction: column; gap: 10px; margin-bottom: 14px; }
.opt {
  min-height: 48px; text-align: left; padding: 10px 14px;
  border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text);
  font-size: .92rem; line-height: 1.6; cursor: pointer;
}
.opt.picked { border-color: var(--primary); background: var(--primary-weak); }
.opt.locked { opacity: 1; }
.opt.correct { border-color: var(--green); background: var(--green-weak); }
.opt.wrongpick { border-color: var(--red); background: var(--red-weak); }

.qactions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
.qactions .btn { width: auto; flex: 1; min-width: 120px; }

.verdict {
  border-radius: 10px; padding: 12px; font-size: .9rem; font-weight: 700;
  margin-top: 4px;
}
.verdict.ok { background: var(--green-weak); border: 1px solid var(--green-line); color: var(--green); }
.verdict.bad { background: var(--red-weak); border: 1px solid var(--red-line); color: var(--red); }

.ansbox { margin-top: 12px; font-size: .9rem; }
.ansbox .lbl { display: block; font-weight: 700; color: var(--primary); margin-bottom: 4px; font-size: .8rem; }
.ansbox.ana { border-top: 1px dashed var(--line); padding-top: 10px; }

.submitted-hint {
  margin-top: 10px; font-size: .78rem; color: var(--muted);
  background: var(--bg); border-radius: 8px; padding: 6px 10px;
}

.draft-ta, .note-ta {
  width: 100%; min-height: 96px; margin-top: 10px;
  border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text);
  padding: 10px 12px; font-size: .9rem; font-family: inherit; line-height: 1.6;
  resize: vertical;
}
.note-editor { margin-top: 8px; }
.selftip { font-size: .78rem; color: var(--muted); margin-top: 8px; }
.grades { display: flex; gap: 8px; margin-top: 10px; }
.grade {
  flex: 1; min-height: 46px; border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text); font-size: .9rem; cursor: pointer;
}
.grade.on { border-color: var(--orange); background: var(--orange-weak); color: var(--orange); }

/* ===================== 筛选抽屉 ===================== */
.mask {
  position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 40;
  opacity: 0; pointer-events: none; transition: opacity .2s;
}
.mask.show { opacity: 1; pointer-events: auto; }
.drawer {
  position: fixed; top: 0; right: 0; bottom: 0; width: 82%; max-width: 360px;
  background: var(--card); z-index: 41;
  transform: translateX(100%); transition: transform .22s ease;
  display: flex; flex-direction: column;
  padding-bottom: var(--safe-b);
}
.drawer.open { transform: translateX(0); }
.drawer-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 16px; border-bottom: 1px solid var(--line);
}
.drawer-head b { font-size: .95rem; }
.drawer-close {
  min-height: 44px; min-width: 44px; border: none; background: none;
  color: var(--muted); font-size: 1.3rem; cursor: pointer;
}
.drawer-body { flex: 1; overflow-y: auto; padding: 14px 16px; }
.drawer-body h3 { font-size: .8rem; color: var(--muted); margin: 14px 0 8px; }
.drawer-body select {
  width: 100%; min-height: 46px; border: 1.5px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text); font-size: .9rem; padding: 0 10px;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  min-height: 44px; padding: 8px 14px; border: 1.5px solid var(--line); border-radius: 999px;
  background: var(--card); color: var(--text); font-size: .86rem; cursor: pointer;
}
.chip.on { border-color: var(--primary); background: var(--primary-weak); color: var(--primary); }
.switch-row { display: flex; align-items: center; gap: 10px; margin-top: 12px; font-size: .88rem; }
.switch-row input { width: 20px; height: 20px; accent-color: var(--red); }
.drawer-foot { padding: 12px 16px; border-top: 1px solid var(--line); }

/* ===================== 错题页 ===================== */
.wrong-tabs { display: flex; gap: 6px; margin-bottom: 12px; }
.wt {
  flex: 1; min-height: 44px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--card); color: var(--text); font-size: .88rem; cursor: pointer;
}
.wt.active { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 700; }
.wrong-item { border-bottom: 1px solid var(--line); padding: 12px 0; }
.wrong-item:last-child { border-bottom: none; }
.wi-top { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.wi-q { font-size: .9rem; margin: 8px 0 6px; line-height: 1.6; }
.wi-meta { font-size: .76rem; color: var(--muted); margin-bottom: 8px; }
.wi-btns { display: flex; gap: 8px; }
.tag.st { color: var(--green); }
.tag.st:empty { display: none; }

/* ===================== 我的页 ===================== */
.mine-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; font-size: .88rem; }
.mine-row .val { color: var(--muted); font-size: .82rem; text-align: right; }
.stat-cards { display: flex; gap: 10px; margin-bottom: 12px; }
.stat-card { flex: 1; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.stat-card .num { font-size: 1.05rem; font-weight: 700; }
.stat-card .cap { font-size: .72rem; color: var(--muted); margin-top: 2px; }
.err-line { font-size: .76rem; color: var(--red); padding: 2px 0; }
.fsize-row { display: flex; gap: 6px; align-items: center; }
.fsize-row label {
  min-height: 44px; display: inline-flex; align-items: center; gap: 4px;
  border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; font-size: .82rem;
}
.fsize-row input { accent-color: var(--primary); }

/* ===================== 底部导航 ===================== */
.tabbar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 30;
  background: var(--card); border-top: 1px solid var(--line);
  display: flex; max-width: 520px; margin: 0 auto;
  padding-bottom: var(--safe-b);
}
.tabbar .tab {
  flex: 1; min-height: 56px; border: none; background: none;
  color: var(--muted); font-size: .8rem; cursor: pointer;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px;
}
.tabbar .tab .ic { font-size: 1.15rem; line-height: 1; }
.tabbar .tab.active { color: var(--primary); font-weight: 700; }

/* ===================== Toast ===================== */
#toast {
  position: fixed; left: 50%; bottom: calc(80px + var(--safe-b)); transform: translateX(-50%);
  background: rgba(30,32,38,.92); color: #fff;
  padding: 10px 18px; border-radius: 999px; font-size: .85rem;
  opacity: 0; pointer-events: none; transition: opacity .2s; z-index: 60;
  max-width: 90%; text-align: center;
}
#toast.show { opacity: 1; }

@media (prefers-color-scheme: dark) {
  #toast { background: rgba(240,242,245,.92); color: #121417; }
}

/* ===== R10 保存状态 ===== */
.save-state { font-size: .72rem; margin-left: auto; color: #8a9099; min-width: 3.4em; text-align: right; }
.save-state.saving { color: #b0832f; }
.save-state.saved { color: #2e9e5b; }
.save-state.unsaved { color: #d04545; font-weight: 600; }

/* ===== 错题页收藏筛选 ===== */
.wrong-tabs .wt.fav-filter { margin-left: auto; }
.wrong-tabs .wt.fav-filter.on { background: #2f6fed; color: #fff; border-color: #2f6fed; }

/* ===== 05 课件知识点卡片 ===== */
.know-card {
  margin-top: 12px; border: 1px solid #d8e0ee; border-radius: 12px;
  background: #f7f9fd; overflow: hidden;
}
.know-head {
  padding: 9px 12px; font-weight: 700; font-size: .92rem;
  background: #eaf1fd; color: #1f4fa8; border-bottom: 1px solid #d8e0ee;
}
.know-section { padding: 10px 12px; border-top: 1px dashed #d3dcea; }
.know-section:first-of-type { border-top: 0; }
.know-title { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 6px; }
.know-title b { font-size: .95rem; color: #17233d; }
.know-badge {
  font-size: .68rem; font-weight: 600; color: #1f7a45; background: #e2f5ea;
  border: 1px solid #b6e3c8; border-radius: 999px; padding: 1px 8px;
}
.know-block { margin: 6px 0; }
.know-lbl { font-weight: 700; font-size: .82rem; color: #33405c; margin-bottom: 3px; }
.know-points { margin: 2px 0 0; padding-left: 1.2em; }
.know-points li { margin: 3px 0; line-height: 1.55; font-size: .88rem; }
.know-use { font-size: .88rem; line-height: 1.6; color: #2b3550; background: #eef4ff; border-radius: 8px; padding: 7px 9px; }
.know-block.formula { overflow-x: auto; }
.know-block.formula ul { padding-left: 1.2em; margin: 2px 0; }
.know-block.formula li { font-size: .86rem; line-height: 1.55; white-space: nowrap; }
details.know-quote, details.know-pitfall {
  margin: 6px 0; border: 1px solid #d8e0ee; border-radius: 8px; background: #fff;
}
details.know-quote summary, details.know-pitfall summary {
  cursor: pointer; padding: 7px 10px; font-size: .82rem; font-weight: 600; color: #3a5a9e;
  list-style: revert; padding-left: 10px;
}
details.know-quote blockquote {
  margin: 0; padding: 8px 10px; border-top: 1px dashed #d8e0ee;
  font-size: .85rem; line-height: 1.7; color: #333; background: #fbfcfe;
  white-space: pre-wrap;
}
details.know-pitfall ul { margin: 4px 0; padding-left: 1.4em; }
details.know-pitfall li { font-size: .84rem; line-height: 1.6; margin: 3px 0; }
.know-source {
  margin-top: 7px; font-size: .72rem; color: #6b7280; line-height: 1.5;
  border-top: 1px dotted #d3dcea; padding-top: 6px; word-break: break-all;
}
.know-missing { padding: 10px 12px; font-size: .84rem; color: #8a6d1f; background: #fdf6e3; line-height: 1.6; }
.know-warn { padding: 10px 12px; font-size: .84rem; color: #9a3b2f; background: #fdeceb; line-height: 1.6; }
.know-pendingflag {
  margin: 0 12px 8px; font-size: .76rem; color: #9a5b14; background: #fdf0dc;
  border-radius: 8px; padding: 6px 9px; line-height: 1.5;
}
.verdict.mid { background: #eef2f8; color: #33405c; }

@media (prefers-color-scheme: dark) {
  .know-card { border-color: #33405c; background: #1b2233; }
  .know-head { background: #22304d; color: #bcd2ff; border-color: #33405c; }
  .know-section { border-color: #2c3852; }
  .know-title b { color: #e6ebf5; }
  .know-lbl { color: #c4cfe4; }
  .know-points li { color: #d6dcea; }
  .know-use { background: #22304d; color: #dbe4f5; }
  details.know-quote, details.know-pitfall { border-color: #33405c; background: #20283b; }
  details.know-quote blockquote { background: #1b2233; color: #d6dcea; border-color: #33405c; }
  .know-missing, .know-warn, .know-pendingflag { filter: brightness(.92); }
}