:root {
  --bg: #f4f6fb;
  --panel: #ffffff;
  --line: #e4e8f0;
  --text: #1c2434;
  --muted: #6b7688;
  --accent: #3b6ef6;
  --accent-soft: #e8efff;
  --green: #16a34a;
  --green-soft: #e7f7ec;
  --amber: #d97706;
  --amber-soft: #fdf3e2;
  --red: #dc2626;
  --red-soft: #fdecec;
  --purple: #7c3aed;
  --purple-soft: #f1ecfe;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 30, 60, .04), 0 8px 24px rgba(20, 30, 60, .06);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 14px;
  line-height: 1.6;
}

button, input, select, textarea { font: inherit; color: inherit; }
a { color: var(--accent); }

/* ---------- 顶栏 ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 12px 24px;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 190px; }
.logo { font-size: 26px; }
.brand-name { font-weight: 700; font-size: 16px; letter-spacing: .5px; }
.brand-sub { font-size: 11px; color: var(--muted); }
.tabs { display: flex; gap: 4px; flex-wrap: wrap; }
.user-area { display: flex; align-items: center; gap: 12px; margin-left: auto; }
.user-name { font-size: 12.5px; color: var(--muted); white-space: nowrap; }
.tab {
  border: 0;
  background: transparent;
  padding: 7px 14px;
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
  white-space: nowrap;
}
.tab:hover { background: #eef2f9; color: var(--text); }
.tab.active { background: var(--accent); color: #fff; font-weight: 600; }

/* ---------- 主体 ---------- */
main { padding: 26px 28px 70px; max-width: 1120px; margin: 0 auto; }
.panel.hidden, .hidden { display: none !important; }

.banner {
  margin: 12px 24px 0;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--amber-soft);
  color: #8a5a00;
  border: 1px solid #f2d9a8;
  font-size: 13px;
}

/* ---------- 工具栏 ---------- */
.toolbar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.toolbar .grow { flex: 1; }
.result-bar { color: var(--muted); font-size: 12.5px; margin: 4px 2px 12px; }
.muted { color: var(--muted); font-size: 12.5px; }
.grow { flex: 1; }

.input, .select {
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  outline: none;
}
.input:focus, .select:focus, textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.input.search { width: 260px; }
.check { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); cursor: pointer; user-select: none; }
.check input { accent-color: var(--accent); }

/* ---------- 按钮 ---------- */
.btn {
  height: 36px;
  padding: 0 14px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--panel);
  cursor: pointer;
  transition: .15s;
  white-space: nowrap;
}
.btn:hover { border-color: #c9d4e8; background: #f8faff; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.btn.primary:hover { background: #2f5ee0; }
.btn.ghost { background: transparent; }
.btn.danger { color: var(--red); border-color: #f3c9c9; background: #fff7f7; }
.btn.danger:hover { background: var(--red-soft); }
.btn.tiny { height: 28px; padding: 0 10px; font-size: 12.5px; border-radius: 8px; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; }
.icon-btn {
  border: 0;
  background: transparent;
  font-size: 18px;
  cursor: pointer;
  color: var(--muted);
  padding: 4px 8px;
  border-radius: 8px;
}
.icon-btn:hover { background: #f0f3fa; color: var(--text); }
.link {
  border: 0; background: transparent; color: var(--accent);
  cursor: pointer; padding: 0 6px; font-size: 13.5px;
}
.link.danger { color: var(--red); }
.link:hover { text-decoration: underline; }

/* ---------- 卡片 ---------- */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 14px; }
#item-list, #answers-list {
  grid-template-columns: 1fr;
  max-width: 920px;
  margin: 0 auto;
  gap: 20px;
}
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.card.pad { padding: 18px; }
.card h3 { margin: 0 0 6px; font-size: 15px; }

/* ---------- 错题卡 ---------- */
.item-card { padding: 26px 30px; display: flex; flex-direction: column; gap: 14px; border-radius: 18px; }
.item-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.item-head .grow { flex: 1; }
.item-source { font-size: 12.5px; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; max-width: 100%; }
.badge {
  font-size: 12px;
  padding: 3px 11px;
  border-radius: 999px;
  font-weight: 600;
  white-space: nowrap;
}
.badge.subject-化学 { background: var(--green-soft); color: var(--green); }
.badge.subject-物理 { background: var(--accent-soft); color: var(--accent); }
.badge.subject-数学 { background: var(--purple-soft); color: var(--purple); }
.badge.subject-其他 { background: #eef1f6; color: var(--muted); }
.badge.st-new { background: var(--red-soft); color: var(--red); }
.badge.st-reviewing { background: var(--amber-soft); color: var(--amber); }
.badge.st-mastered { background: var(--green-soft); color: var(--green); }
.badge.diff { background: #f2f4f9; color: var(--muted); }
.badge.topic { background: #eef3ff; color: #3556a8; font-weight: 500; }
.badge.cause { background: #fff3f3; color: #b4453c; font-weight: 500; }

.q-text {
  font-weight: 600;
  white-space: pre-wrap;
  font-size: 17.5px;
  line-height: 1.85;
  letter-spacing: .1px;
  user-select: text;
  color: #121a2a;
}
.chips { display: flex; gap: 6px; flex-wrap: wrap; }
.answer-line {
  font-size: 14.5px;
  background: #f7f9fd;
  border: 1px dashed var(--line);
  border-radius: 10px;
  padding: 12px 16px;
  white-space: pre-wrap;
  line-height: 1.75;
}
.answer-line b { color: var(--green); }
.mine-line { font-size: 14px; color: var(--muted); white-space: pre-wrap; line-height: 1.7; }
.answer-hidden {
  font-size: 12.5px;
  color: var(--muted);
  background: #f7f9fd;
  border-radius: 8px;
  padding: 6px 10px;
}
.thumbs { display: flex; gap: 10px; flex-wrap: wrap; }
.item-card .thumb {
  width: auto; height: auto; max-width: 420px; min-width: 180px;
  border-radius: 12px; background: #f7f9fd; cursor: zoom-in;
}
.item-card .thumb img { width: 100%; height: auto; object-fit: contain; display: block; border-radius: 12px; }
.thumbs-toggle { align-self: flex-start; font-size: 12px; }
.q-actions { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.thumb {
  width: 74px; height: 74px; border-radius: 9px; overflow: hidden;
  border: 1px solid var(--line); background: #f0f3fa; cursor: zoom-in;
  display: flex; align-items: center; justify-content: center;
}
.thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.thumb.ph { color: var(--muted); font-size: 11px; }

/* ---------- 知识点卡 ---------- */
.topic-card { padding: 16px 18px; }
.topic-card h3 { display: flex; align-items: center; gap: 8px; }
.topic-meta { margin: 8px 0; }
.topic-block { margin-top: 8px; font-size: 13px; }
.topic-block .label { display: block; font-size: 11.5px; color: var(--muted); font-weight: 600; letter-spacing: .5px; }
.topic-block .value { white-space: pre-wrap; }
.topic-actions { display: flex; align-items: center; gap: 8px; margin-top: 10px; }
.topic-count { font-size: 12px; color: var(--accent); cursor: pointer; }

/* ---------- Mark Scheme ---------- */
.scheme-list { display: flex; flex-direction: column; gap: 12px; }
.scheme-card { padding: 14px 16px; }
.scheme-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 8px; }
.scheme-items { display: flex; flex-direction: column; gap: 6px; }
.scheme-item {
  display: flex; gap: 8px; align-items: flex-start;
  padding: 7px 10px; border-radius: 9px; background: #f8fafd; font-size: 13px;
}
.scheme-item.missed { background: var(--red-soft); }
.scheme-item .flag { width: 16px; flex: 0 0 16px; text-align: center; }

/* ---------- 复习 ---------- */
.review-top {
  display: flex; align-items: center; gap: 16px;
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 14px 18px; margin-bottom: 14px; box-shadow: var(--shadow);
}
.review-info { flex: 1; font-size: 14px; }
.review-info b { color: var(--accent); font-size: 18px; }
.review-stage { max-width: 820px; }
.review-card { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 22px; }
.review-progress { font-size: 12.5px; color: var(--muted); margin-bottom: 10px; }
.review-question { font-size: 16px; font-weight: 600; white-space: pre-wrap; margin-bottom: 12px; }
.review-block { margin: 14px 0; padding: 12px 14px; border-radius: 10px; background: #f7f9fd; white-space: pre-wrap; }
.review-block h4 { margin: 0 0 6px; font-size: 12.5px; color: var(--muted); letter-spacing: .5px; }
.review-block.good { background: var(--green-soft); }
.review-block.bad { background: #fdf1f1; }
.review-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }
.review-empty { text-align: center; color: var(--muted); padding: 50px 0; }

/* ---------- 统计 ---------- */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin-bottom: 14px; }
.stat-card { padding: 18px; }
.stat-num { font-size: 28px; font-weight: 700; line-height: 1.2; }
.stat-label { color: var(--muted); font-size: 12.5px; }
.bars { display: flex; flex-direction: column; gap: 9px; }
.bar-row { display: grid; grid-template-columns: 150px 1fr 46px; align-items: center; gap: 10px; font-size: 12.5px; }
.bar-track { height: 10px; border-radius: 999px; background: #eef1f7; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 999px; background: var(--accent); }
.bar-fill.red { background: var(--red); }
.bar-fill.amber { background: var(--amber); }
.bar-fill.green { background: var(--green); }
.bar-fill.purple { background: var(--purple); }
.bar-num { text-align: right; color: var(--muted); }

/* ---------- 设置 ---------- */
.settings-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 14px; }
.danger-card { border-color: #f3c9c9; }
.tips { margin: 0; padding-left: 18px; color: var(--muted); font-size: 12.5px; }
.tips li { margin: 4px 0; }

/* ---------- 弹窗 ---------- */
.modal { position: fixed; inset: 0; z-index: 60; display: flex; align-items: center; justify-content: center; padding: 20px; }
.modal-mask { position: absolute; inset: 0; background: rgba(18, 24, 38, .42); }
.modal-box {
  position: relative;
  background: var(--panel);
  border-radius: 18px;
  width: 860px;
  max-width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 24px 80px rgba(15, 25, 50, .28);
}
.modal-box.narrow { width: 640px; }
.modal-head { display: flex; align-items: center; padding: 16px 20px; border-bottom: 1px solid var(--line); }
.modal-head h2 { margin: 0; font-size: 16px; flex: 1; }
.modal-body { padding: 18px 20px; overflow: auto; }
.modal-foot { display: flex; justify-content: flex-end; gap: 10px; padding: 14px 20px; border-top: 1px solid var(--line); }

.field { display: flex; flex-direction: column; gap: 5px; margin-bottom: 12px; }
.field > span { font-size: 12.5px; color: var(--muted); font-weight: 600; }
.field input, .field select, .field textarea {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 8px 11px;
  background: #fff;
  outline: none;
  width: 100%;
  resize: vertical;
}
.row-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.row-4 { display: grid; grid-template-columns: 1.2fr 1fr 1fr 1fr; gap: 12px; }
.field-head { display: flex; align-items: center; gap: 10px; }
.field-head span { font-size: 12.5px; color: var(--muted); font-weight: 600; flex: 1; }

.ms-list { display: flex; flex-direction: column; gap: 8px; }
.ms-row { display: flex; align-items: center; gap: 8px; }
.ms-row input[type=text] {
  flex: 1; border: 1px solid var(--line); border-radius: 9px;
  padding: 7px 10px; outline: none; background: #fff;
}
.ms-row .missed { display: inline-flex; align-items: center; gap: 5px; color: var(--red); font-size: 12.5px; white-space: nowrap; }
.ms-row .missed input { accent-color: var(--red); }
.ms-row .icon-btn { color: var(--red); }

.chip-group { display: flex; gap: 8px; flex-wrap: wrap; }
.chip {
  padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line);
  background: #fff; cursor: pointer; font-size: 12.5px;
}
.chip.on { background: var(--accent-soft); border-color: #b9ccff; color: #274bb5; font-weight: 600; }

.image-grid { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 8px; }
.image-cell { position: relative; width: 96px; height: 96px; border-radius: 10px; overflow: hidden; border: 1px solid var(--line); background: #f0f3fa; }
.image-cell img { width: 100%; height: 100%; object-fit: cover; display: block; }
.image-cell .rm {
  position: absolute; top: 3px; right: 3px; width: 22px; height: 22px;
  border-radius: 50%; border: 0; background: rgba(20, 26, 40, .6); color: #fff;
  cursor: pointer; font-size: 12px; line-height: 1;
}
.image-actions { display: flex; align-items: center; gap: 12px; }
.hint { color: var(--muted); font-size: 12px; }

#modal-image { background: transparent; }
#modal-image .modal-mask { background: rgba(10, 14, 24, .82); }
#modal-image img { position: relative; max-width: 94vw; max-height: 92vh; border-radius: 10px; box-shadow: 0 20px 60px rgba(0,0,0,.5); }

/* ---------- toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%);
  background: #1f2937; color: #fff; padding: 10px 18px; border-radius: 999px;
  font-size: 13px; z-index: 99; box-shadow: 0 10px 30px rgba(0,0,0,.25);
}
.toast.err { background: var(--red); }
.toast.ok { background: #157347; }

/* ---------- 空状态 ---------- */
.empty {
  grid-column: 1 / -1;
  text-align: center;
  color: var(--muted);
  padding: 60px 20px;
  background: var(--panel);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
}
.empty h3 { color: var(--text); margin: 0 0 8px; }

/* ---------- 收件箱 ---------- */
.inbox-tip { margin: -2px 2px 14px; line-height: 1.7; }
.inbox-grid { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.inbox-card { padding: 12px; display: flex; flex-direction: column; gap: 8px; }
.thumb.big { width: 100%; height: 180px; border-radius: 10px; }
.thumb.big img { object-fit: contain; background: #f7f9fd; }
.inbox-meta { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.inbox-meta .select { height: 30px; padding: 0 8px; font-size: 12.5px; }
.inbox-note {
  width: 100%; border: 1px solid var(--line); border-radius: 9px;
  padding: 7px 10px; resize: vertical; outline: none; font-size: 12.5px;
}
.inbox-note:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.inbox-actions { display: flex; align-items: center; }
#panel-inbox.drop-hot { outline: 2px dashed var(--accent); outline-offset: 8px; border-radius: 12px; }

/* ---------- 卡片内答题框 ---------- */
.inline-answer {
  margin-top: 4px; padding: 16px;
  background: #f7f9fd; border: 1px dashed #c9d4e8; border-radius: 12px;
  display: flex; flex-direction: column; gap: 10px;
}
.inline-answer.hidden { display: none !important; }
.inline-answer-text {
  width: 100%; border: 1px solid var(--line); border-radius: 10px;
  padding: 12px 14px; resize: vertical; outline: none; font-size: 15px; line-height: 1.7; background: #fff;
}
.inline-answer-text:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.inline-answer-actions { display: flex; justify-content: flex-end; gap: 8px; }

/* ---------- 作答 / 批改 ---------- */
.answer-question { background: #f7f9fd; border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin-bottom: 14px; }
.answer-q-text { font-weight: 600; white-space: pre-wrap; margin-bottom: 8px; }
.answer-q-text:empty { display: none; }
.graded-box { background: #f7fbf8; border: 1px solid #d6ecdd; border-radius: 10px; padding: 10px 12px; display: flex; flex-direction: column; gap: 8px; }
.score-row { display: flex; align-items: baseline; gap: 10px; }
.score-num { font-size: 22px; font-weight: 700; color: var(--accent); }

#paste-text {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font-family: Consolas, "Courier New", monospace;
  font-size: 12.5px;
  line-height: 1.6;
  resize: vertical;
  outline: none;
}
#paste-text:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }

.answer-box { display: flex; flex-direction: column; gap: 6px; }
.answer-toggle { align-self: flex-start; }
.ms-view { display: flex; flex-direction: column; gap: 4px; margin-top: 4px; }
.ms-view-item { font-size: 12.5px; background: #f4f7fc; border-radius: 8px; padding: 4px 9px; color: #33405a; }
.ms-view-item.missed { background: var(--red-soft); color: #a03a3a; }

.pending-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

/* ---------- 题目卡片里的批改结果 ---------- */
.grade-box {
  background: #f6fbf8; border: 1px solid #d6ecdd; border-radius: 10px;
  padding: 10px 12px; display: flex; flex-direction: column; gap: 6px;
}
.grade-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.grade-score { font-size: 20px; font-weight: 700; color: var(--accent); }
.grade-pending {
  font-size: 12.5px; color: var(--amber); background: var(--amber-soft);
  border: 1px solid #f2d9a8; border-radius: 8px; padding: 6px 10px;
}

/* 打印时答案强制展开 */
@media print {
  .answer-box { display: flex !important; }
  .answer-toggle { display: none !important; }
}

/* ---------- 数学公式渲染 ---------- */
.frac {
  display: inline-flex; flex-direction: column; vertical-align: middle;
  text-align: center; margin: 0 .18em; font-size: .95em; line-height: 1.15;
}
.frac .num { border-bottom: 1px solid currentColor; padding: 0 .18em; }
.frac .den { padding: 0 .18em; }
.sqrt { white-space: nowrap; }
.sqrt .radicand { border-top: 1px solid currentColor; padding: 0 .12em; }
.q-text sup, .q-text sub, .answer-line sup, .answer-line sub, .mine-line sup, .mine-line sub,
.ms-view-item sup, .ms-view-item sub, .review-question sup, .review-question sub { font-size: .72em; }

/* ---------- 响应式 ---------- */
@media (max-width: 760px) {
  .topbar { flex-direction: column; align-items: flex-start; gap: 10px; padding: 10px 14px; }
  main { padding: 14px 14px 50px; }
  .input.search { width: 100%; }
  .row-2, .row-4 { grid-template-columns: 1fr; }
  .card-grid { grid-template-columns: 1fr; }
  .bar-row { grid-template-columns: 110px 1fr 40px; }
  .toolbar { gap: 8px; }
}

/* ---------- 打印 ---------- */
@media print {
  .topbar, .toolbar, .result-bar, .review-top, .review-actions, .modal, .toast, .banner { display: none !important; }
  body { background: #fff; }
  main { padding: 0; max-width: none; }
  .card-grid { display: block; }
  .item-card { box-shadow: none; border-radius: 0; border: 0; border-bottom: 1px solid #ccc; break-inside: avoid; padding: 10px 0; }
  .thumb { width: 60px; height: 60px; }
}

/* ================= 新版布局：左侧栏 + 内容区（参考学习平台） ================= */
.topbar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: 238px;
  flex-direction: column;
  align-items: stretch;
  gap: 18px;
  padding: 24px 16px;
  background: #fff;
  border-right: 1px solid var(--line);
  border-bottom: 0;
  overflow-y: auto;
  backdrop-filter: none;
}
.brand { min-width: 0; padding: 0 8px 10px; }
.brand-name { font-size: 18px; }
.brand-sub { font-size: 11.5px; }
.tabs { flex-direction: column; gap: 4px; }
.tab { text-align: left; padding: 11px 14px; border-radius: 10px; font-size: 14px; }
.tab:hover { background: #f2f5fb; }
.tab.active { background: var(--accent-soft); color: #2b4bb0; font-weight: 600; }
.user-area {
  margin-top: auto;
  flex-direction: column;
  align-items: flex-start;
  gap: 8px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}
main { margin: 0 0 0 238px; max-width: 1180px; padding: 34px 42px 90px; }
#item-list, #answers-list { max-width: 880px; }
.item-card { border-radius: 16px; box-shadow: 0 2px 10px rgba(20, 30, 60, .05); }
.item-head { padding-bottom: 8px; border-bottom: 1px solid #f0f3f9; }
.answer-toggle, .btn.tiny { height: 34px; }

@media (max-width: 900px) {
  .topbar {
    position: static; width: auto; flex-direction: row; flex-wrap: wrap;
    gap: 10px; padding: 10px 14px;
    border-right: 0; border-bottom: 1px solid var(--line);
  }
  .tabs { flex-direction: row; }
  .user-area { margin-top: 0; margin-left: auto; flex-direction: row; border-top: 0; padding-top: 0; }
  main { margin-left: 0; padding: 16px 14px 60px; }
}
/* ================= IB DP 科目徽章配色 ================= */
.badge.s-chem { background: var(--green-soft); color: var(--green); }
.badge.s-phys { background: var(--accent-soft); color: var(--accent); }
.badge.s-math { background: var(--purple-soft); color: var(--purple); }
.badge.s-bio  { background: #e9f7ef; color: #1a7f4b; }
.badge.s-cs   { background: #eef0ff; color: #4250c7; }
.badge.s-hum  { background: #fdf1e6; color: #b4671a; }
.badge.s-art  { background: #fdecf5; color: #b23a7a; }
.badge.s-lang { background: #e9f5fb; color: #1f6f99; }
.badge.s-other { background: #eef1f6; color: var(--muted); }
/* ================= 按知识点分组 ================= */
#item-list.grouped { display: block; max-width: 920px; }
.topic-group { margin-bottom: 34px; }
.topic-group-head {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 4px 2px 10px; margin-bottom: 14px;
  border-bottom: 1px solid #e8edf5;
}
.topic-group-head h3 { margin: 0; font-size: 17px; }
.topic-group-head .grow { flex: 1; }
.group-list { display: flex; flex-direction: column; gap: 16px; }
/* ================= 作答图片（手写/绘图） ================= */
.inline-answer-actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.answer-thumbs { display: flex; gap: 6px; flex-wrap: wrap; }
.ans-thumb { position: relative; width: 56px; height: 56px; border-radius: 8px; overflow: visible; }
.ans-thumb img { width: 56px; height: 56px; object-fit: cover; border-radius: 8px; border: 1px solid var(--line); }
.ans-thumb button {
  position: absolute; top: -6px; right: -6px; width: 18px; height: 18px; border-radius: 50%;
  border: 0; background: rgba(20,26,40,.75); color: #fff; font-size: 10px; line-height: 1; cursor: pointer;
}
/* ================= 公式编辑器 ================= */
.modal-box.wide { width: min(760px, 94vw); }
.formula-preview {
  min-height: 74px; display: flex; align-items: center; justify-content: center;
  padding: 14px 16px; margin-bottom: 10px;
  background: #f7f9fd; border: 1px dashed var(--line); border-radius: 10px;
  overflow-x: auto; font-size: 18px;
}
#formula-input {
  width: 100%; border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 12px; font-family: ui-monospace, Consolas, monospace;
  font-size: 13px; line-height: 1.6; resize: vertical; outline: none; margin-bottom: 12px;
}
.kbd-groups { display: flex; flex-direction: column; gap: 10px; max-height: 260px; overflow-y: auto; }
.kbd-group { display: flex; flex-direction: column; gap: 6px; }
.kbd-title { font-size: 12px; font-weight: 600; color: var(--muted); }
.kbd-grid { display: flex; flex-wrap: wrap; gap: 6px; }
.kbd {
  min-width: 46px; height: 34px; padding: 0 10px;
  border: 1px solid var(--line); background: #fff; border-radius: 9px;
  font-size: 13px; cursor: pointer; color: var(--text);
  transition: background .12s, border-color .12s;
}
.kbd:hover { background: var(--accent-soft); border-color: #c3d2f0; }
.kbd:active { transform: translateY(1px); }
/* ---------- 公式键盘（分页，参考 SaveMyExams） ---------- */
.formula-box { width: min(860px, 96vw); }
.fq-quick { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 12px; }
.fq-tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 12px; flex-wrap: wrap; }
.fq-tab {
  border: 0; background: transparent; padding: 9px 14px; font-size: 14px;
  color: var(--muted); cursor: pointer; border-bottom: 2px solid transparent; border-radius: 8px 8px 0 0;
}
.fq-tab:hover { background: #f2f5fb; }
.fq-tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.fq-pad {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px;
  max-height: 360px; overflow-y: auto; padding: 2px;
}
.fq-key {
  position: relative; min-height: 56px; border: 1px solid var(--line); background: #fff;
  border-radius: 10px; font-size: 17px; cursor: pointer; color: var(--text);
  display: flex; align-items: center; justify-content: center; transition: background .12s, border-color .12s;
}
.fq-key:hover { background: var(--accent-soft); border-color: #c3d2f0; }
.fq-key:active { transform: translateY(1px); }
.fq-key.quick { min-height: 34px; font-size: 13px; padding: 0 12px; }
.fq-hint { position: absolute; top: 4px; right: 7px; font-size: 10px; color: var(--accent); }
.fq-label { font-size: 17px; line-height: 1; }
.fq-tools { display: flex; gap: 6px; margin-top: 12px; }

@media (max-width: 640px) {
  .fq-pad { grid-template-columns: repeat(4, 1fr); }
  .fq-key { min-height: 48px; font-size: 16px; }
}
/* ---------- 题干/小题/分小题作答 ---------- */
.q-text-sub { font-weight: 600; }
.parts-hint { font-size: 12.5px; color: var(--muted); }
.answer-part { display: flex; gap: 10px; align-items: flex-start; }
.answer-part .part-label { min-width: 26px; font-weight: 700; color: var(--accent); padding-top: 9px; }
.answer-part .inline-answer-text { flex: 1; }
/* ---------- 小题与其答题框紧挨着 ---------- */
.q-part { display: flex; flex-direction: column; gap: 6px; margin-top: 2px; }
.q-part .q-text-sub { margin: 0; }
.q-part .inline-answer-text { width: 100%; background: #fff; }
.part-actions { margin-top: 6px; }