/* ================================================================
   考研数学二 · 试卷讲义风（Exam Paper Editorial）
   暖纸底 + 坐标纸网格 / 蓝黑墨水 + 朱砂红双墨色 /
   楷体标题 / 密封线装饰 / 「已掌握」红印章 / 得分栏 / 目录点线
   ================================================================ */
:root {
  --paper: #f5f0e3;
  --paper-2: #fdfaf2;
  --ink: #2f2a21;
  --muted: #8a8170;
  --navy: #33547e;
  --navy-deep: #26436a;
  --navy-soft: rgba(51, 84, 126, .08);
  --red: #bf3a2b;
  --red-deep: #9e2c1f;
  --red-soft: rgba(191, 58, 43, .08);
  --ochre: #9a6b0f;
  --ochre-soft: rgba(196, 148, 48, .18);
  --hair: rgba(47, 42, 33, .16);
  --hair-strong: rgba(47, 42, 33, .3);
  --grid: rgba(51, 84, 126, .055);
  --shadow: 0 2px 10px rgba(84, 62, 28, .07);
  --shadow-lg: 0 14px 40px rgba(60, 44, 18, .14);
  --r: 8px;
  --r-sm: 6px;
  --kai: 'LXGW WenKai Screen', 'Kaiti SC', 'STKaiti', KaiTi, 'FZKai-Z03S', serif;
  --mono: ui-monospace, 'SF Mono', 'Cascadia Mono', Consolas, 'Courier New', monospace;
}
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; padding: 0; min-height: 100%; }
body {
  font-family: 'PingFang SC', 'MiSans', 'HarmonyOS Sans SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  color: var(--ink); font-size: 15px;
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 28px 28px;
  -webkit-font-smoothing: antialiased;
}
::selection { background: rgba(191, 58, 43, .22); }
::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: rgba(47, 42, 33, .22); border-radius: 8px; border: 2px solid var(--paper); }
::-webkit-scrollbar-track { background: transparent; }
button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--navy); outline-offset: 2px; border-radius: 4px; }

/* ---------- 密封线（宽屏装饰） ---------- */
.seal-line {
  position: fixed; left: 16px; top: 50%; transform: translateY(-50%);
  writing-mode: vertical-rl; z-index: 1;
  font-family: var(--kai); font-size: 12px; letter-spacing: 12px;
  color: rgba(191, 58, 43, .38);
  border-left: 1.5px dashed rgba(191, 58, 43, .35);
  padding: 6px 0 6px 10px; height: min(72vh, 620px);
  user-select: none; pointer-events: none; display: none;
}
@media (min-width: 1360px) { .seal-line { display: block; } }

/* ---------- 顶部页眉 ---------- */
#topbar {
  position: sticky; top: 0; z-index: 90;
  background: rgba(250, 246, 236, .92);
  -webkit-backdrop-filter: blur(10px) saturate(130%);
  backdrop-filter: blur(10px) saturate(130%);
  border-bottom: 3px double rgba(47, 42, 33, .4);
}
.tb-inner {
  max-width: 980px; margin: 0 auto; padding: 0 20px; height: 56px;
  display: flex; align-items: center; gap: 14px;
}
.brand {
  appearance: none; border: none; background: none; padding: 0; cursor: pointer;
  display: flex; align-items: center; gap: 11px; min-width: 0;
}
.brand .seal {
  width: 31px; height: 31px; flex-shrink: 0; border-radius: 7px;
  background: var(--red); color: #fdf6e9;
  font-family: var(--kai); font-size: 19px; font-weight: 700;
  display: inline-flex; align-items: center; justify-content: center;
  box-shadow: inset 0 0 0 1.5px rgba(253, 246, 233, .5), 0 1px 3px rgba(158, 44, 31, .3);
}
.brand-t {
  font-family: var(--kai); font-size: 17px; font-weight: 700;
  letter-spacing: .06em; color: var(--ink); white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}
.tb-nav { margin-left: auto; display: flex; align-items: center; gap: 2px; }
.tb-btn {
  appearance: none; border: none; background: none; cursor: pointer;
  font-size: 13.5px; color: var(--muted); padding: 9px 11px; border-radius: 7px;
  display: inline-flex; align-items: center; gap: 7px; line-height: 1;
  user-select: none; -webkit-user-select: none; touch-action: manipulation;
  transition: color .15s, background .15s, box-shadow .15s;
}
.tb-btn:hover { color: var(--ink); background: rgba(47, 42, 33, .06); }
.tb-btn.active {
  color: var(--red); font-weight: 600;
  box-shadow: inset 0 -2.5px 0 var(--red);
  background: rgba(191, 58, 43, .05);
}
.tb-user.logged .tb-t { color: var(--navy-deep); font-weight: 600; }
.kbd {
  font-family: var(--mono); font-size: 10px; color: var(--muted);
  border: 1px solid var(--hair-strong); border-bottom-width: 2px; border-radius: 4px;
  padding: 2px 5px; line-height: 1; letter-spacing: .5px;
}
@media (max-width: 900px), (hover: none) { .kbd { display: none; } }

#layout { min-height: 100vh; }
#main { max-width: 880px; margin: 0 auto; padding: 32px 28px 90px; min-width: 0; counter-reset: secno; }

/* ---------- 页头 ---------- */
.breadcrumb { font-family: var(--mono); font-size: 12px; color: var(--muted); margin-bottom: 16px; letter-spacing: .3px; }
.breadcrumb span:hover { color: var(--red); }
.page-head { margin-bottom: 20px; }
.ph-kicker {
  font-family: var(--mono); font-size: 11px; letter-spacing: .22em;
  color: var(--red); margin-bottom: 10px; text-transform: uppercase;
}
.ph-kicker::before {
  content: ""; display: inline-block; width: 26px; height: 2px;
  background: var(--red); margin-right: 10px; vertical-align: 3px;
}
h2.ch-title {
  font-family: var(--kai); font-size: 29px; font-weight: 700;
  letter-spacing: .04em; margin: 0 0 8px; line-height: 1.3;
}
.t-no {
  font-family: var(--mono); font-size: 15px; font-weight: 500;
  color: var(--red); margin-right: 12px; letter-spacing: .05em;
}
.ch-meta {
  color: var(--muted); font-size: 13px; margin-bottom: 4px;
  display: flex; gap: 6px 14px; flex-wrap: wrap; align-items: center; line-height: 1.7;
}
.ch-meta a {
  color: var(--navy-deep); text-decoration: none; white-space: nowrap;
  border-bottom: 1px dashed rgba(51, 84, 126, .5); padding-bottom: 1px;
  transition: color .15s, border-color .15s;
}
.ch-meta a:hover { color: var(--red); border-color: var(--red); }
.notice {
  background: var(--red-soft); border: 1px solid rgba(191, 58, 43, .28);
  border-left: 3px solid var(--red); color: #7c3a30;
  padding: 12px 15px; border-radius: var(--r-sm);
  margin: 14px 0 18px; font-size: 13.5px; line-height: 1.7;
}

/* ---------- 得分栏 ---------- */
.score-strip {
  display: flex; flex-wrap: wrap;
  border: 2px solid var(--ink); border-radius: 6px;
  background: var(--paper-2); margin: 6px 0 26px; overflow: hidden;
}
.score-cell { flex: 1 1 120px; padding: 13px 18px 12px; min-width: 0; }
.score-cell + .score-cell { border-left: 1px solid var(--hair); }
.score-cell i { display: block; font-style: normal; font-size: 11.5px; color: var(--muted); letter-spacing: .12em; margin-bottom: 5px; }
.score-cell b { font-family: var(--mono); font-size: 24px; font-weight: 600; line-height: 1; letter-spacing: .02em; }
.score-cell b.c-red { color: var(--red); }
.score-cell .me-den { font-size: 14px; color: var(--muted); font-weight: 400; font-style: normal; }

/* ---------- 目录（总览 / 我的章节） ---------- */
.toc-tools { display: flex; justify-content: flex-end; gap: 8px; margin: 0 0 6px; }
.toc, .me-chapters { border-top: 2px solid var(--ink); }
.toc-row, .me-ch {
  position: relative; display: flex; align-items: baseline; gap: 12px;
  padding: 15px 8px 17px; border-bottom: 1px solid var(--hair);
  cursor: pointer; overflow: hidden;
  transition: background .15s;
  animation: rowIn .45s both;
  animation-delay: calc(var(--i, 0) * 35ms);
}
.toc-row:hover, .me-ch:hover { background: rgba(191, 58, 43, .045); }
.toc-idx {
  font-family: var(--mono); font-size: 13px; color: var(--muted);
  width: 2.1em; flex-shrink: 0; transition: color .15s;
}
.toc-row:hover .toc-idx, .me-ch:hover .toc-idx { color: var(--red); }
.toc-name, .me-ch-name {
  font-family: var(--kai); font-size: 18px; font-weight: 500; color: var(--ink);
  min-width: 0; overflow-wrap: anywhere; line-height: 1.45;
}
.toc-dots {
  flex: 1; min-width: 24px; align-self: flex-end;
  border-bottom: 2px dotted rgba(47, 42, 33, .28);
  transform: translateY(-5px);
}
.toc-meta, .me-ch-n { font-family: var(--mono); font-size: 12px; color: var(--muted); white-space: nowrap; flex-shrink: 0; }
.toc-meta b, .me-ch-n b { color: var(--red); font-weight: 600; }
.toc-bar { position: absolute; left: 0; bottom: -1px; height: 2.5px; background: var(--red); opacity: .85; }
@keyframes rowIn { from { opacity: 0; transform: translateY(7px); } to { opacity: 1; } }
.sec-label {
  font-size: 12px; color: var(--muted); font-weight: 600; letter-spacing: .1em;
  margin: 20px 0 4px;
}
.sec-label::before { content: "§ "; color: var(--red); font-family: var(--kai); }

/* ---------- 标签 ---------- */
.tag { font-size: 11px; border-radius: 5px; padding: 2px 8px; flex-shrink: 0; line-height: 1.5; }
.tag.uncertain { color: var(--ochre); background: var(--ochre-soft); border: 1px solid rgba(154, 107, 15, .3); }
.tag.fb { color: var(--muted); background: rgba(47, 42, 33, .06); border: 1px solid var(--hair); }

/* ---------- 方法卡 ---------- */
.topic {
  position: relative;
  background: var(--paper-2);
  border: 1px solid var(--hair-strong); border-radius: var(--r);
  margin-bottom: 12px;
  box-shadow: var(--shadow);
  transition: box-shadow .18s ease;
}
.topic:hover { box-shadow: var(--shadow-lg); }
.topic.mastered {
  border-color: rgba(191, 58, 43, .45);
  background: linear-gradient(180deg, rgba(191, 58, 43, .045), rgba(191, 58, 43, .015)), var(--paper-2);
}
.topic-head { display: flex; align-items: center; gap: 10px; padding: 13px 16px; cursor: pointer; min-height: 48px; }
.topic-head .idx { font-family: var(--mono); color: var(--red); font-size: 12.5px; flex-shrink: 0; width: 2.4em; }
.topic-head .t-name { font-weight: 600; font-size: 15.5px; flex: 1; min-width: 0; overflow-wrap: anywhere; }
.tag.m-done {
  font-family: var(--kai); font-weight: 700; font-size: 12px; letter-spacing: .2em;
  color: var(--red); background: rgba(191, 58, 43, .06);
  border: 1.5px solid rgba(191, 58, 43, .7); border-radius: 6px;
  box-shadow: inset 0 0 0 1px rgba(191, 58, 43, .22);
  padding: 2px 8px 2px 10px; display: inline-block;
  transform: rotate(-4deg);
}
.topic-head .arrow { color: var(--muted); transition: transform .2s; flex-shrink: 0; }
.topic.closed .topic-head .arrow { transform: rotate(-90deg); }
.topic-body { padding: 2px 18px 15px; border-top: 1px dashed var(--hair); }
.topic.closed .topic-body { display: none; }

/* 分组：一、二、三… */
.sec-group { margin-bottom: 24px; }
.sec-head {
  display: flex; align-items: center; gap: 10px; cursor: pointer; user-select: none;
  padding: 10px 6px; margin-bottom: 12px; min-height: 44px;
  border-bottom: 1px solid var(--hair-strong);
  counter-increment: secno;
}
.sec-head .s-name { font-family: var(--kai); font-weight: 700; font-size: 17.5px; letter-spacing: .03em; }
.sec-head .s-name::before { content: counter(secno, cjk-ideographic) "、 "; color: var(--red); }
.sec-head .cnt { font-family: var(--mono); font-size: 11.5px; color: var(--muted); }
.sec-head .arrow { color: var(--muted); transition: transform .2s; margin-left: auto; }
.sec-group.closed .sec-head .arrow { transform: rotate(-90deg); }
.sec-group.closed .sec-body { display: none; }
/* PDF 重点知识整理节点：朱砂红标注，置顶于各节 */
.pdf-group .sec-head {
  counter-increment: none;
  background: var(--red-soft);
  border: 1px solid rgba(191, 58, 43, .32);
  border-left: 4px solid var(--red);
  border-radius: var(--r-sm);
  border-bottom: 1px solid rgba(191, 58, 43, .32);
  padding: 10px 12px;
}
.pdf-group .sec-head .s-name { color: var(--red-deep); }
.pdf-group .sec-head .cnt { color: var(--red); font-weight: 600; }
.pdf-group .sec-head .arrow { color: var(--red); }

/* ---------- 题库 ---------- */
.q-bank {
  background: var(--paper-2);
  border: 1px solid rgba(51, 84, 126, .3); border-radius: var(--r);
  margin: 4px 0 16px; overflow: hidden;
}
.q-bank-head {
  display: flex; justify-content: space-between; align-items: center; cursor: pointer; user-select: none;
  padding: 11px 14px; font-weight: 600; font-size: 13.5px; color: var(--navy-deep);
  background: var(--navy-soft); min-height: 44px;
}
.q-bank-head .arrow { color: var(--muted); transition: transform .2s; }
.q-bank.closed > .q-bank-head .arrow { transform: rotate(-90deg); }
.q-bank > .q-bank-body { padding: 2px 14px 12px; border-top: 1px solid var(--hair); max-height: 70vh; overflow-y: auto; }
.q-bank.closed > .q-bank-body { display: none; }
.q-note { color: var(--muted); font-size: 12.5px; padding: 8px 2px; line-height: 1.7; }
.q-item {
  border: 1px solid var(--hair); border-radius: var(--r-sm); background: var(--paper-2);
  margin: 8px 0;
}
.q-head {
  display: flex; align-items: center; gap: 8px; padding: 10px 12px; cursor: pointer; min-height: 44px; border-radius: var(--r-sm);
  min-width: 0;
}
.q-head:hover { background: rgba(51, 84, 126, .05); }
.q-head .q-src {
  font-size: 11px; color: var(--ochre); background: var(--ochre-soft);
  border: 1px solid rgba(154, 107, 15, .25); border-radius: 4px;
  padding: 1px 7px; white-space: nowrap;
  flex: 0 1 auto; min-width: 0; max-width: 48%;
  overflow: hidden; text-overflow: ellipsis;
}
.q-head .q-prev { font-size: 13px; color: var(--muted); flex: 1 1 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
.q-head .arrow { color: var(--muted); flex-shrink: 0; margin-left: auto; }
.q-body { padding: 2px 14px 12px; border-top: 1px dashed var(--hair); }
.q-stem { line-height: 1.8; margin: 8px 0; overflow-x: auto; overflow-y: hidden; -webkit-overflow-scrolling: touch; }
.q-opts { display: flex; flex-direction: column; gap: 4px; margin: 8px 0; }
.q-opt { line-height: 1.6; padding: 5px 10px; border-radius: 5px; overflow-wrap: anywhere; }
.q-opt.correct { background: var(--red-soft); }
.q-opt.correct b { color: var(--red); }
.q-ans { margin: 8px 0 4px; font-size: 13.5px; }
.q-ans b { color: var(--red); }
.q-exp { line-height: 1.75; color: #4a4436; overflow-x: auto; overflow-y: hidden; -webkit-overflow-scrolling: touch; }
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 2px 0; margin: .5em 0; }

/* ---------- 文本组件 ---------- */
ul.steps { margin: 4px 0; padding-left: 20px; }
ul.steps li { margin: 5px 0; line-height: 1.7; overflow-wrap: anywhere; }
ul.steps li::marker { color: var(--navy); }
ul.feats { margin: 4px 0; padding: 0; list-style: none; display: flex; flex-wrap: wrap; gap: 6px; }
ul.feats li {
  background: var(--navy-soft); color: var(--navy-deep); font-size: 12.5px;
  border-radius: 5px; padding: 3px 10px; border: 1px solid rgba(51, 84, 126, .22);
}
ul.pits { margin: 4px 0; padding-left: 20px; }
ul.pits li { color: #a03d2e; line-height: 1.65; overflow-wrap: anywhere; }
ul.pits li::marker { color: var(--red); }
.topic-body .q-bank { margin: 10px 0 4px; }

/* ---------- 按钮 ---------- */
.topic-actions { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; }
.btn {
  border: 1.5px solid var(--hair-strong); border-radius: var(--r-sm);
  padding: 7px 14px; font-size: 13px; min-height: 36px;
  cursor: pointer; color: var(--ink); text-decoration: none;
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--paper-2);
  transition: color .15s, border-color .15s, background .15s, transform .1s;
}
.btn:hover { color: var(--navy-deep); border-color: var(--navy); }
.btn:active { transform: scale(.97); }
.btn.btn-ghost { border-color: transparent; background: transparent; color: var(--muted); min-height: 32px; padding: 5px 10px; }
.btn.btn-ghost:hover { color: var(--red); background: var(--red-soft); border-color: transparent; }
.btn.btn-ghost.on { color: var(--navy-deep); background: var(--navy-soft); border-color: rgba(51, 84, 126, .35); }
.btn.btn-stamp {
  font-family: var(--kai); font-weight: 700; letter-spacing: .15em;
  color: var(--red); border-color: rgba(191, 58, 43, .6);
  background: rgba(191, 58, 43, .05);
}
.btn.btn-stamp:hover { background: var(--red-soft); border-color: var(--red); color: var(--red-deep); }
.btn.master-btn.mastered {
  font-family: var(--kai); font-weight: 700; letter-spacing: .1em;
  color: var(--red); border-color: rgba(191, 58, 43, .65);
  background: var(--red-soft);
}
.muted { color: var(--muted); font-size: 12.5px; }

/* ---------- 大纲视图 ---------- */
.ol-tools { display: flex; gap: 8px; align-items: center; margin-bottom: 18px; flex-wrap: wrap; }
.ol-root { margin-bottom: 18px; }
.ol-root > .ol-root-head {
  font-family: var(--kai); font-weight: 700; font-size: 17px; letter-spacing: .03em;
  padding: 13px 16px 13px 20px; min-height: 52px;
  background: var(--paper-2);
  border: 1px solid var(--hair-strong); border-left: 4px solid var(--red);
  border-radius: var(--r-sm);
  box-shadow: var(--shadow);
  cursor: pointer; position: relative;
  transition: box-shadow .18s ease;
}
.ol-root > .ol-root-head:hover { box-shadow: var(--shadow-lg); }
.ol-root > .ol-root-head .ol-arrow { width: 26px; height: 26px; font-size: 12px; }
.ol-root > .ol-body { margin: 8px 0 0 13px; }

.ol-node { margin: 1px 0; }
.ol-row {
  display: flex; align-items: center; gap: 9px; padding: 7px 10px; border-radius: 7px;
  cursor: pointer; line-height: 1.5; min-height: 42px;
  transition: background .12s;
}
.ol-row:hover { background: var(--navy-soft); }
.ol-row .ol-arrow {
  width: 22px; height: 22px; border-radius: 50%; flex-shrink: 0;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 10px; color: var(--navy-deep);
  background: var(--paper-2); border: 1px solid var(--hair-strong);
}
.ol-row.flat { cursor: default; }
.ol-row.flat:hover { background: transparent; }
.ol-row.flat .ol-arrow { background: transparent; border: none; box-shadow: none; }
.ol-row.flat .ol-arrow::before { content: "·"; color: rgba(47, 42, 33, .4); font-size: 18px; line-height: 0; }
.ol-row .ol-name { flex: 1; min-width: 0; overflow-wrap: anywhere; }
.ol-row .ol-q {
  font-size: 11px; font-weight: 600; color: var(--navy-deep);
  background: var(--navy-soft); border: 1px solid rgba(51, 84, 126, .3);
  border-radius: 4px; padding: 2.5px 8px; flex-shrink: 0;
}
.ol-row .ol-c {
  font-size: 11px; font-weight: 600; color: var(--red-deep);
  background: var(--red-soft); border: 1px solid rgba(191, 58, 43, .3);
  border-radius: 4px; padding: 2.5px 8px; flex-shrink: 0;
}
.ol-body { margin-left: 12px; padding-left: 17px; border-left: 2px solid rgba(51, 84, 126, .3); border-radius: 2px; }
.ol-lv1 > .ol-body, .ol-lv3 > .ol-body { border-left-color: rgba(51, 84, 126, .36); }
.ol-lv2 > .ol-body, .ol-lv4 > .ol-body { border-left-color: rgba(191, 58, 43, .4); }
.ol-node.ol-pdf > .ol-row .ol-name { color: var(--red-deep); font-weight: 700; }
.ol-node.ol-pdf > .ol-row .ol-arrow { color: var(--red-deep); background: var(--red-soft); border-color: rgba(191, 58, 43, .45); }
.ol-node.ol-pdf > .ol-row .ol-c { font-weight: 700; }
.ol-node.ol-pdf > .ol-row:hover { background: var(--red-soft); }
.ol-lv1 > .ol-row { font-size: 15.2px; font-weight: 700; padding: 9px 10px; min-height: 46px; }
.ol-lv1 > .ol-row .ol-arrow { width: 24px; height: 24px; font-size: 11px; }
.ol-lv2 > .ol-row { font-size: 14.3px; font-weight: 600; }
.ol-lv3 > .ol-row { font-size: 13.6px; font-weight: 500; }
.ol-lv4 > .ol-row { font-size: 13.2px; font-weight: 400; }
.ol-lv4 > .ol-row .ol-arrow { width: 19px; height: 19px; }
.ol-cards { margin: 6px 0 10px; }
.ol-cards .topic { margin-bottom: 10px; }
.ol-qbank { margin: 4px 0 12px; }
.q-more {
  text-align: center; font-size: 13px; color: var(--navy-deep); cursor: pointer;
  padding: 10px; margin: 6px 0 8px; border-radius: var(--r-sm); user-select: none;
  background: var(--navy-soft); border: 1px dashed rgba(51, 84, 126, .4);
}
.q-more:hover { background: rgba(51, 84, 126, .13); }

/* ---------- 登录 / 注册 ---------- */
.auth-wrap { display: flex; justify-content: center; padding: 6vh 0 30px; }
.auth-card {
  width: min(420px, 100%); padding: 24px 26px 20px;
  background: var(--paper-2);
  border: 1px solid var(--hair-strong); border-radius: 10px;
  box-shadow: var(--shadow-lg);
  position: relative;
}
.auth-card::before {
  content: ""; display: block; border-top: 3px double rgba(47, 42, 33, .45);
  margin: -24px -26px 20px; border-radius: 10px 10px 0 0;
}
.auth-tabs { display: flex; border-bottom: 1.5px solid var(--hair-strong); margin-bottom: 20px; }
.auth-tab {
  flex: 1; appearance: none; border: none; background: transparent;
  font-family: var(--kai); font-size: 16px; font-weight: 700; letter-spacing: .3em;
  color: var(--muted); padding: 10px 0 12px; cursor: pointer;
  position: relative; transition: color .15s;
}
.auth-tab.on { color: var(--red); }
.auth-tab.on::after {
  content: ""; position: absolute; left: 30%; right: 30%; bottom: -1.5px; height: 3px;
  background: var(--red); border-radius: 2px;
}
.auth-form { display: flex; flex-direction: column; gap: 18px; }
.blank { display: flex; flex-direction: column; gap: 7px; }
.blank > span { font-size: 12px; color: var(--muted); letter-spacing: .12em; }
.blank input {
  border: none; border-bottom: 1.5px solid rgba(191, 58, 43, .45);
  border-radius: 0; background: transparent; padding: 7px 2px;
  font-family: var(--kai); font-size: 16.5px; color: var(--ink); min-height: 38px;
  outline: none; transition: border-color .15s;
  caret-color: var(--red);
}
.blank input:focus { border-bottom-color: var(--red); box-shadow: 0 1.5px 0 var(--red); }
.auth-submit {
  justify-content: center; font-family: var(--kai); font-weight: 700;
  font-size: 15px; letter-spacing: .4em; text-indent: .4em; min-height: 42px;
  background: var(--red); color: #fdf6e9; border-color: var(--red);
  box-shadow: 0 2px 8px rgba(158, 44, 31, .25);
}
.auth-submit:hover { background: var(--red-deep); color: #fff; border-color: var(--red-deep); }
.auth-submit:disabled { opacity: .6; cursor: default; }
.auth-msg { font-size: 12.5px; color: var(--red); min-height: 18px; text-align: center; }
.auth-note { font-size: 12px; color: var(--muted); text-align: center; line-height: 1.7; }
.auth-note::before { content: "※ "; color: var(--red); }

/* ---------- 访客注册弹窗 ---------- */
#auth-ov { position: fixed; inset: 0; z-index: 90; display: none; }
body.auth-open { overflow: hidden; }
body.auth-open #auth-ov { display: flex; align-items: center; justify-content: center; padding: 20px; }
#auth-ov .so-backdrop { background: rgba(36, 30, 20, .5); }
.auth-modal {
  position: relative; width: min(430px, 94vw); max-height: 92vh; overflow-y: auto;
  border-radius: 10px;
  animation: authIn .3s cubic-bezier(.18, .89, .32, 1.14) both;
}
@keyframes authIn { from { opacity: 0; transform: translateY(20px) scale(.95); } to { opacity: 1; transform: none; } }
.auth-modal .auth-card { margin: 0; }
.auth-close {
  position: absolute; top: -13px; right: -13px; z-index: 2;
  appearance: none; width: 32px; height: 32px; border-radius: 50%; cursor: pointer;
  border: 1.5px solid var(--hair-strong); background: var(--paper-2); color: var(--muted); font-size: 13px;
  box-shadow: 0 4px 14px rgba(40, 30, 12, .22);
  transition: transform .18s ease, color .18s ease, border-color .18s ease;
}
.auth-close:hover { color: var(--red); border-color: var(--red); transform: rotate(90deg); }
.guest-strip {
  margin: 0 0 16px; padding: 11px 18px;
  border: 1.5px dashed rgba(191, 58, 43, .55); border-radius: var(--r-sm);
  background: rgba(191, 58, 43, .05);
  color: var(--ink); font-size: 13.5px; letter-spacing: .04em; text-align: center;
}
.guest-strip::before { content: "✦ "; color: var(--red); }

/* ---------- 收藏（还不熟的题） ---------- */
.q-fav {
  appearance: none; flex-shrink: 0; width: 26px; height: 26px; border-radius: 50%;
  border: 1.5px solid var(--hair); background: transparent; cursor: pointer;
  color: var(--muted); font-size: 14px; line-height: 1; padding: 0;
  transition: color .15s, border-color .15s, background .15s, transform .15s;
}
.q-fav:hover { color: var(--red); border-color: var(--red); transform: scale(1.12); }
.q-fav.on { color: var(--red); border-color: rgba(191, 58, 43, .55); background: rgba(191, 58, 43, .08); }
.q-filter {
  display: flex; align-items: center; gap: 12px;
  padding: 8px 12px; margin: 2px 0 6px;
  border-bottom: 1px dashed var(--hair-strong);
}
.qf-btn {
  appearance: none; cursor: pointer; font-family: var(--kai); font-size: 13px;
  color: var(--muted); background: transparent; padding: 4px 12px;
  border: 1.5px dashed var(--hair-strong); border-radius: 999px;
  transition: color .15s, border-color .15s, background .15s;
}
.qf-btn:hover { color: var(--red); border-color: var(--red); }
.qf-btn.on { color: var(--red); border-color: var(--red); background: rgba(191, 58, 43, .07); }
.qf-n { font-size: 12px; color: var(--muted); font-family: var(--mono); }

/* ---------- 收藏页工具条 + 勾选导出 ---------- */
.fv-tools {
  display: flex; align-items: center; gap: 6px; flex-wrap: wrap;
  margin: 0 0 4px; padding: 8px;
  background: var(--paper-2); border: 1px solid var(--hair); border-radius: var(--r-sm);
}
.fv-tools .btn { min-height: 34px; padding: 6px 7px; min-width: 66px; justify-content: center; font-size: 12.5px; }
.fv-tools .btn-stamp { flex: 1; min-width: 0; }
.fv-meta { font-family: var(--mono); font-size: 12px; color: var(--muted); margin: 10px 2px 14px; min-height: 15px; }
.q-pick {
  appearance: none; background: transparent; border: none; cursor: pointer;
  font-size: 16px; line-height: 1; padding: 2px 4px; color: var(--muted);
  flex: none;
}
.q-pick:hover { color: var(--navy-deep); }
.q-pick.on { color: var(--navy); }
.fav-group .sec-body { padding: 0 2px; }

/* ---------- 随机出题 · 组卷 ---------- */
.quiz-panel {
  margin: -6px 0 6px; padding: 14px 16px 16px;
  border: 1px dashed var(--hair-strong); border-top: none; border-radius: 0 0 var(--r-sm) var(--r-sm);
  background: var(--paper-2);
}
#me-quiz { border-bottom-left-radius: 0; border-bottom-right-radius: 0; }
#me-quiz + .quiz-panel[hidden] { display: none; }
.qz-modes { display: flex; flex-direction: column; gap: 8px; margin-bottom: 12px; }
.qz-mode {
  display: flex; gap: 10px; align-items: flex-start; cursor: pointer;
  padding: 9px 12px; border: 1px solid var(--hair); border-radius: var(--r-sm);
  transition: border-color .15s, background .15s;
}
.qz-mode:hover { border-color: var(--navy); }
.qz-mode:has(input:checked) { border-color: var(--navy); background: var(--navy-soft); }
.qz-mode input { margin-top: 4px; accent-color: var(--navy-deep); }
.qz-mode b { display: block; font-family: var(--kai); font-size: 14.5px; letter-spacing: .02em; }
.qz-mode i { display: block; font-style: normal; font-size: 12px; color: var(--muted); margin-top: 2px; line-height: 1.6; }
.qz-actions { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.qz-n { font-size: 13.5px; color: var(--ink); }
.qz-n select {
  font-family: var(--mono); font-size: 13px; padding: 5px 8px;
  border: 1px solid var(--hair-strong); border-radius: var(--r-sm); background: var(--paper-2); color: var(--ink);
}
.qz-note { font-size: 12px; color: var(--muted); margin-bottom: 14px; }
.qz-head {
  display: flex; justify-content: space-between; align-items: baseline; gap: 10px;
  font-family: var(--kai); font-weight: 700; font-size: 13.5px; color: var(--navy-deep);
  padding: 8px 10px; margin-bottom: 8px;
  background: var(--navy-soft); border-radius: var(--r-sm);
}
.qz-head span:last-child { font-family: var(--mono); font-weight: 400; font-size: 11px; color: var(--muted); }
.daily-strip {
  margin: 0 0 16px; padding: 12px 16px 8px;
  border: 1.5px dashed rgba(191, 58, 43, .5); border-radius: var(--r-sm);
  background: rgba(191, 58, 43, .04);
}
.ds-head { display: flex; align-items: center; gap: 10px; margin-bottom: 4px; }
.ds-t { font-weight: 700; color: var(--red); font-size: 14px; letter-spacing: .04em; }
.ds-x {
  appearance: none; margin-left: auto; width: 24px; height: 24px; border-radius: 50%;
  border: 1px solid var(--hair); background: transparent; cursor: pointer;
  color: var(--muted); font-size: 11px; line-height: 1; padding: 0;
}
.ds-x:hover { color: var(--red); border-color: var(--red); }
.ds-body { padding-bottom: 4px; }
.fav-entry {
  display: flex; align-items: baseline; gap: 12px; cursor: pointer;
  padding: 15px 8px 17px; margin-top: 14px;
  border: 1.5px dashed rgba(191, 58, 43, .45); border-radius: var(--r-sm);
  background: rgba(191, 58, 43, .035);
  transition: background .15s;
}
.fav-entry:hover { background: rgba(191, 58, 43, .08); }
.fav-entry .fe-star { color: var(--red); }
.fav-entry .fe-t { font-weight: 600; }
.fav-entry .me-ch-n { margin-left: auto; color: var(--muted); font-size: 13px; }
.fav-entry .me-ch-n b { color: var(--red); font-family: var(--mono); }

/* ---------- 我的页 ---------- */
.role-seal, .role-tag {
  display: inline-block; vertical-align: 6px; margin-left: 14px;
  font-size: 12px; letter-spacing: .2em; padding: 3px 10px 3px 12px;
  border-radius: 6px; font-family: var(--kai);
}
.role-seal {
  font-weight: 700; color: var(--red);
  border: 1.5px solid rgba(191, 58, 43, .7); background: rgba(191, 58, 43, .06);
  box-shadow: inset 0 0 0 1px rgba(191, 58, 43, .22);
  transform: rotate(-3deg);
}
.role-tag { color: var(--muted); border: 1px solid var(--hair-strong); }
.me-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 22px; }

/* ---------- 界面风格切换（纸质手册 ⇄ 日光面板） ---------- */
.style-card {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  margin-top: 22px; padding: 14px 16px;
  background: var(--paper-2);
  border: 1px solid var(--hair-strong); border-radius: var(--r-sm);
  box-shadow: var(--shadow);
}
.style-card .sc-icon {
  flex: none; width: 34px; height: 34px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; color: var(--red);
  border: 1.5px solid rgba(191, 58, 43, .5); border-radius: 8px;
  background: var(--red-soft);
}
.style-card .sc-body { flex: 1; min-width: 0; }
.style-card .sc-t { font-weight: 600; }
.style-card .sc-d { margin-top: 2px; font-size: 12.5px; color: var(--muted); }
.sc-seg {
  flex: none; display: flex; overflow: hidden;
  border: 1px solid var(--hair-strong); border-radius: var(--r-sm);
  background: var(--paper);
}
.sc-opt {
  appearance: none; border: none; background: transparent; cursor: pointer;
  font-family: var(--kai); font-size: 13.5px; letter-spacing: .05em;
  color: var(--muted); padding: 7px 13px; transition: background .15s, color .15s;
}
.sc-opt + .sc-opt { border-left: 1px solid var(--hair); }
.sc-opt:not(.on):hover { color: var(--red); background: var(--red-soft); }
.sc-opt.on { background: var(--red); color: #fdf6e9; font-weight: 700; cursor: default; }
.auth-col { width: min(420px, 100%); display: flex; flex-direction: column; gap: 16px; }

/* ---------- 管理后台 ---------- */
.adm-table {
  background: var(--paper-2);
  border: 2px solid var(--ink); border-radius: var(--r-sm);
  box-shadow: var(--shadow);
  overflow-x: auto;
}
.adm-table table { width: 100%; border-collapse: collapse; font-size: 13.5px; min-width: 560px; }
.adm-table th, .adm-table td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--hair); }
.adm-table th {
  font-size: 11.5px; color: var(--muted); font-weight: 600; white-space: nowrap;
  letter-spacing: .12em; background: rgba(47, 42, 33, .035);
  border-bottom: 1.5px solid var(--hair-strong);
}
.adm-table tbody tr:last-child td { border-bottom: none; }
.adm-table tbody tr:hover { background: rgba(51, 84, 126, .04); }
.adm-name { font-weight: 600; overflow-wrap: anywhere; }
.adm-table td b { color: var(--red); font-family: var(--mono); font-weight: 600; }
.adm-table .tag.m-done { transform: none; font-size: 10.5px; padding: 1px 6px 1px 8px; letter-spacing: .1em; }

/* ---------- 管理后台：公告卡 + 重置密码行内编辑 ---------- */
.adm-notice {
  background: var(--paper-2);
  border: 2px solid var(--ink); border-radius: var(--r-sm);
  box-shadow: var(--shadow);
  padding: 14px 16px 16px; margin: 0 0 18px;
}
.adm-notice-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; margin-bottom: 10px; }
.adm-notice-head b { font-family: var(--kai); font-size: 15.5px; letter-spacing: .06em; }
.adm-notice-text {
  width: 100%; box-sizing: border-box; resize: vertical;
  border: 1.5px solid rgba(191, 58, 43, .45); border-radius: 6px;
  background: rgba(255, 253, 245, .6); padding: 9px 11px;
  font-family: var(--kai); font-size: 14.5px; line-height: 1.8; color: var(--ink);
  outline: none; transition: border-color .15s;
}
.adm-notice-text:focus { border-color: var(--red); }
.adm-notice .me-actions { margin-top: 10px; }
.adm-pw-edit { display: flex; flex-direction: column; gap: 8px; min-width: 150px; }
.adm-pw-input {
  width: 100%; box-sizing: border-box;
  border: none; border-bottom: 1.5px solid rgba(191, 58, 43, .45);
  border-radius: 0; background: transparent; padding: 5px 2px;
  font-family: var(--kai); font-size: 14px; color: var(--ink);
  outline: none; caret-color: var(--red);
}
.adm-pw-input:focus { border-bottom-color: var(--red); }
.adm-pw-edit .me-actions { gap: 6px; }

/* ---------- 搜索浮层 ---------- */
#search-ov { position: fixed; inset: 0; z-index: 100; display: none; }
body.search-open #search-ov { display: block; }
.so-backdrop {
  position: absolute; inset: 0; background: rgba(36, 30, 20, .42);
  -webkit-backdrop-filter: blur(3px);
  backdrop-filter: blur(3px);
}
.so-panel {
  position: relative; margin: max(9vh, 48px) auto 0; width: min(620px, calc(100% - 28px));
  border-radius: 10px; overflow: hidden;
  background: var(--paper-2);
  border: 1px solid var(--hair-strong);
  box-shadow: 0 24px 70px rgba(40, 30, 12, .38);
  animation: soIn .18s ease;
}
@keyframes soIn { from { opacity: 0; transform: translateY(-8px) scale(.985); } to { opacity: 1; } }
.so-top { display: flex; align-items: center; gap: 8px; padding: 10px 10px 8px 16px; border-bottom: 1px solid var(--hair); }
.so-tabrow { display: flex; gap: 6px; padding: 8px 14px 6px; border-bottom: 1px solid var(--hair); }
.so-tabs { display: flex; gap: 6px; }
#so-input {
  flex: 1; border: none; outline: none; background: transparent;
  font-family: var(--kai); font-size: 17px; padding: 12px 0; color: var(--ink);
  caret-color: var(--red);
}
#so-input::placeholder { color: var(--muted); }
#so-input::-webkit-search-cancel-button { -webkit-appearance: none; appearance: none; }
.so-close {
  appearance: none; border: 1px solid var(--hair); background: transparent;
  width: 32px; height: 32px; border-radius: 50%; cursor: pointer; color: var(--muted); font-size: 13px;
}
.so-close:hover { color: var(--red); border-color: var(--red); }
.so-results { max-height: 56vh; overflow-y: auto; padding: 4px 10px 12px; }
.so-hint { color: var(--muted); font-size: 12.5px; padding: 12px 8px; line-height: 1.7; }
.so-item {
  display: flex; align-items: center; gap: 10px; padding: 10px 12px; border-radius: 7px;
  cursor: pointer; min-height: 42px;
}
.so-item:hover, .so-item.sel { background: var(--navy-soft); }
.so-item .so-name { font-weight: 600; font-size: 14px; min-width: 0; overflow-wrap: anywhere; }
.so-item .so-ch { margin-left: auto; color: var(--muted); font-size: 12px; flex-shrink: 0; }
.so-item .so-ch::before { content: "· "; }
.so-empty { color: var(--muted); font-size: 13px; padding: 14px 8px; }

/* ---------- 章节解锁 ---------- */
.tag.locked {
  color: var(--ochre); background: var(--ochre-soft);
  border: 1px solid rgba(154, 107, 15, .35);
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .08em; white-space: nowrap;
}
.tag.locked::before { content: "🔒 "; font-size: 10px; }
.row-locked .toc-name, .row-locked .me-ch-name { color: var(--muted); }
.row-locked .toc-bar { background: var(--hair-strong); }
.lock-strip {
  border: 1.5px dashed rgba(154, 107, 15, .5); border-radius: var(--r);
  background: var(--ochre-soft); padding: 26px 24px; margin: 10px 0 20px; text-align: center;
}
.lock-strip .ls-t { font-family: var(--kai); font-size: 19px; font-weight: 700; letter-spacing: .1em; color: var(--ochre); }
.lock-strip .ls-msg { margin-top: 10px; font-size: 14px; line-height: 1.8; color: #4a4436; }
.lock-strip .ls-msg b { font-family: var(--mono); color: var(--red); }
.lock-strip .ls-actions { margin-top: 16px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
#lock-ov { position: fixed; inset: 0; z-index: 95; display: none; }
body.lock-open { overflow: hidden; }
body.lock-open #lock-ov { display: flex; align-items: center; justify-content: center; padding: 20px; }
#lock-ov .so-backdrop { background: rgba(36, 30, 20, .5); }
.lock-card { text-align: center; }
.lock-title { font-family: var(--kai); font-size: 21px; font-weight: 700; margin: 0 0 12px; letter-spacing: .06em; }
.lock-msg { font-size: 14.5px; line-height: 1.9; color: #4a4436; }
.lock-msg b { font-family: var(--mono); color: var(--red); font-size: 15px; }

/* ---------- 站点公告弹窗 ---------- */
#notice-ov { position: fixed; inset: 0; z-index: 96; display: none; }
body.notice-open { overflow: hidden; }
body.notice-open #notice-ov { display: flex; align-items: center; justify-content: center; padding: 20px; }
#notice-ov .so-backdrop { background: rgba(36, 30, 20, .5); }
.notice-card { width: min(430px, 100%); }
.notice-body {
  font-size: 14.5px; line-height: 1.9; color: #4a4436;
  white-space: pre-wrap; overflow-wrap: anywhere;
  max-height: 46vh; overflow-y: auto;
  border-top: 1px solid var(--hair); border-bottom: 1px solid var(--hair);
  padding: 12px 2px; margin-bottom: 14px;
}
.lock-card .me-actions { justify-content: center; margin-top: 18px; }
.ol-row.ol-locked .ol-name { color: var(--muted); }
.ol-row.ol-locked:hover { background: var(--ochre-soft); }
.ol-lockcard {
  display: flex; align-items: center; gap: 10px;
  border: 1px dashed var(--hair-strong); border-radius: var(--r);
  background: rgba(47, 42, 33, .03); padding: 11px 14px; margin-bottom: 10px;
  cursor: pointer; font-size: 13.5px; color: var(--muted);
}
.ol-lockcard:hover { background: var(--ochre-soft); }
.search-lock {
  display: flex; align-items: center; gap: 10px; padding: 11px 14px; margin: 4px 0 10px;
  border: 1px dashed var(--hair-strong); border-radius: var(--r); cursor: pointer;
  background: rgba(47, 42, 33, .03); font-weight: 600; font-size: 14.5px;
}
.search-lock:hover { background: var(--ochre-soft); }
.search-lock .s-name { flex: 1; min-width: 0; overflow-wrap: anywhere; }
.q-bank-locked > .q-bank-head { color: var(--muted); background: rgba(47, 42, 33, .04); }
.q-bank-locked > .q-bank-head span { color: var(--muted); }
.adm-unlock.on { color: var(--red); background: var(--red-soft); }

/* ---------- 题目跨卡引用 ---------- */
.q-also { margin: 10px 0 4px; font-size: 12px; color: var(--muted); line-height: 2; }
.q-also a {
  color: var(--navy-deep); text-decoration: none; cursor: pointer;
  border-bottom: 1px dashed rgba(51, 84, 126, .5); margin-right: 2px;
}
.q-also a:hover { color: var(--red); border-color: var(--red); }

/* ---------- 轻提示（纸条） ---------- */
.km2-toast {
  position: fixed; left: 50%; bottom: calc(26px + env(safe-area-inset-bottom, 0px));
  transform: translateX(-50%) translateY(8px);
  background: var(--ink); color: #f6f1e4; font-size: 13px;
  border-left: 3px solid var(--red);
  padding: 10px 16px; border-radius: 6px; z-index: 120;
  box-shadow: var(--shadow-lg);
  opacity: 0; pointer-events: none; transition: opacity .25s, transform .25s;
  max-width: calc(100vw - 40px); text-align: center;
}
.km2-toast.on { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- 跳转高亮 ---------- */
@keyframes flashPulse {
  0%, 55% { box-shadow: 0 0 0 3px rgba(191, 58, 43, .4), var(--shadow-lg); }
  100% { box-shadow: var(--shadow); }
}
.topic.flash, .ol-node.flash { animation: flashPulse 1.8s ease; }

/* ---------- 大纲：返回分支顶层 ---------- */
.ol-backtop {
  position: fixed; right: 20px; bottom: 30px; z-index: 80;
  display: none; align-items: center;
  font-family: var(--kai); font-size: 13px; letter-spacing: .02em;
  color: var(--navy-deep); background: var(--paper-2);
  border: 1px solid var(--hair-strong); border-radius: 999px;
  padding: 10px 16px; cursor: pointer; box-shadow: var(--shadow-lg);
  transition: color .15s, border-color .15s, transform .15s;
}
.ol-backtop.on { display: flex; }
.ol-backtop:hover { color: var(--red); border-color: var(--red); transform: translateY(-2px); }
.ol-node { scroll-margin-top: 64px; }
@media (max-width: 720px) {
  .ol-backtop { right: 12px; bottom: calc(74px + env(safe-area-inset-bottom, 0px)); }
}

/* ---------- 总览来源链接 ---------- */
.ch-meta .src-link {
  color: var(--navy-deep); font-weight: 600; text-decoration: none;
  border-bottom: 1px dashed rgba(51, 84, 126, .5); margin: 0 1px;
}
.ch-meta .src-link:hover { color: var(--red); border-color: var(--red); }

/* ---------- 触控 ---------- */
@media (hover: none) {
  .btn { min-height: 42px; }
  .q-head { padding: 12px; }
  .topic-head { padding: 13px 12px; }
}

/* ---------- 平板 ---------- */
@media (max-width: 1024px) {
  #main { padding: 26px 22px 80px; }
}

/* ---------- 手机 ---------- */
@media (max-width: 720px) {
  .tb-inner { padding: 0 10px; gap: 2px; height: 52px; }
  .brand-t { display: none; }
  .tb-nav { gap: 0; }
  .tb-btn { font-size: 13px; padding: 9px 9px; }
}
@media (max-width: 640px) {
  body { font-size: 15.5px; }
  #main { padding: 18px 14px 70px; }
  h2.ch-title { font-size: 23px; }
  .t-no { font-size: 13px; margin-right: 8px; }
  .ch-meta { gap: 8px 10px; font-size: 12.5px; }
  .score-cell { padding: 11px 14px 10px; flex: 1 1 40%; }
  .score-cell b { font-size: 21px; }
  .score-cell + .score-cell { border-left: none; }
  .score-cell:nth-child(2n) { border-left: 1px solid var(--hair); }
  .score-cell:nth-child(n+3) { border-top: 1px solid var(--hair); }
  .toc-dots { display: none; }
  .toc-name, .me-ch-name { font-size: 16px; }
  .toc-row, .me-ch { gap: 9px; padding: 13px 6px 15px; }
  .toc-meta, .me-ch-n { font-size: 11px; }
  .q-bank > .q-bank-body { max-height: none; overflow: visible; }
  .topic-head { padding: 12px; gap: 8px; }
  .topic-head .t-name { font-size: 14.5px; }
  .topic-body { padding: 2px 12px 13px; }
  .ol-row { padding: 8px 6px; }
  .topic-actions .btn { flex: 1 1 auto; justify-content: center; }
  .auth-wrap { padding: 2vh 0 16px; }
  .auth-card { padding: 18px 18px 16px; }
  .auth-card::before { margin: -18px -18px 18px; }
  .style-card { margin-top: 16px; padding: 12px 14px; gap: 10px 12px; }
  .sc-seg { width: 100%; }
  .sc-opt { flex: 1; padding: 8px 0; }
  .so-panel { margin-top: max(6vh, 24px); }
}
@media (max-width: 400px) {
  .tb-btn { padding: 9px 7px; font-size: 12.5px; }
}

/* ---------- 答案折叠 / 间隔回顾 / 题目搜索 ---------- */
.q-actions { margin: 10px 0 4px; }
.q-secret[hidden] { display: none !important; }
.q-rate {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  margin: 10px 0 2px; padding: 8px 10px;
  background: var(--navy-soft); border-radius: var(--r-sm);
  border: 1px dashed rgba(51, 84, 126, .3);
}
.q-rate .qr-t { font-size: 12.5px; color: var(--navy-deep); margin-right: 2px; }
.q-rate .qr-btn.on {
  color: var(--red); border-color: var(--red);
  background: var(--red-soft); font-weight: 600;
}
.so-tab {
  appearance: none; border: 1px solid var(--hair-strong); background: transparent;
  border-radius: 999px; padding: 6px 12px; font-size: 12.5px; color: var(--muted);
  cursor: pointer; min-height: 32px;
}
.so-tab.on {
  color: var(--red); border-color: rgba(191, 58, 43, .55);
  background: var(--red-soft); font-weight: 600;
}
.so-group-head {
  display: flex; align-items: baseline; gap: 8px; margin: 10px 0 2px; padding: 7px 10px;
  background: var(--navy-soft); border-radius: 6px;
  font-family: var(--kai); font-weight: 700; font-size: 13px; color: var(--navy-deep); letter-spacing: .05em;
}
.so-group-head .so-gn { margin-left: auto; font-family: var(--mono); font-weight: 400; font-size: 11px; color: var(--muted); }
.so-q-list .q-item { margin: 6px 0; }

/* ---------- 章节历年真题面板 ---------- */
.q-zhen { border-color: rgba(191, 58, 43, .35); }
.q-zhen .q-bank-head span:first-child { color: var(--red); }
.z-head {
  display: flex; align-items: baseline; gap: 8px; margin: 14px 0 4px; padding: 7px 10px;
  background: var(--red-soft); border-radius: 6px;
  font-family: var(--kai); font-weight: 700; font-size: 13.5px; color: var(--red); letter-spacing: .06em;
}
.z-head .z-gn { margin-left: auto; font-family: var(--mono); font-weight: 400; font-size: 11px; color: var(--ochre); }

/* ---------- 品牌短标题 / 底栏 / 章节工具 ---------- */
.brand-short { display: none; font-family: var(--kai); font-size: 15px; font-weight: 700; letter-spacing: .08em; }
@media (max-width: 720px) {
  .brand-t { display: none; }
  .brand-short { display: inline; }
  #main { padding-bottom: 96px; }
}
#botnav {
  display: none;
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 95;
  background: rgba(250, 246, 236, .96);
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
  border-top: 1px solid var(--hair-strong);
  padding: 6px 8px calc(6px + env(safe-area-inset-bottom));
  grid-template-columns: repeat(4, 1fr); gap: 2px;
}
@media (max-width: 720px) {
  #botnav { display: grid; }
  .tb-nav .tb-btn:not(.tb-user):not(#tb-search) { display: none; }
}
.bn-btn {
  appearance: none; border: none; background: transparent; cursor: pointer;
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 6px 4px; min-height: 48px; color: var(--muted); font-size: 11px;
  border-radius: 8px;
}
.bn-btn .bn-i { font-size: 16px; line-height: 1; }
.bn-btn.active { color: var(--red); font-weight: 600; background: var(--red-soft); }

.ch-tools {
  display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0 12px;
  position: sticky; top: 56px; z-index: 40;
  background: rgba(245, 240, 227, .92);
  -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
  padding: 6px 0;
}
.skel-line {
  height: 14px; border-radius: 6px; margin: 12px 0;
  background: linear-gradient(90deg, rgba(47,42,33,.06), rgba(47,42,33,.12), rgba(47,42,33,.06));
  background-size: 200% 100%;
  animation: skel 1.2s ease infinite;
}
.skel-line.short { width: 55%; }
@keyframes skel { from { background-position: 200% 0; } to { background-position: -200% 0; } }

.breadcrumb [data-go-home] { cursor: pointer; }
.breadcrumb [data-go-home]:hover { color: var(--red); }

.topic-head:focus-visible { outline-offset: -2px; }
.sec-head:focus-visible { outline-offset: -2px; }

@media (max-width: 720px) {
  .q-head { gap: 6px; padding: 10px 8px; }
  .q-head .q-src { max-width: 42%; font-size: 10.5px; padding: 1px 6px; }
  .q-head .q-prev { font-size: 12.5px; }
  .q-bank > .q-bank-body { max-height: none; overflow: visible; }
  .ch-tools { top: 52px; }

  /* 手机：每级保留可辨识的缩进步进，靠层级导引线区分上下级 */
  .ol-root > .ol-body { margin-left: 2px; }
  .ol-body {
    margin-left: 4px !important;
    padding-left: 11px !important;
    border-left-width: 2px;
  }
  /* 深层节点标题不再额外左右加 padding，尽量用满宽度 */
  .ol-lv3 > .ol-row,
  .ol-lv4 > .ol-row { padding-left: 4px; padding-right: 4px; }
  .ol-row { padding-left: 6px; padding-right: 6px; }
  .ol-cards { margin-left: 0; margin-right: 0; }
  .ol-body .topic,
  .ol-body .q-bank,
  .ol-qbank {
    margin-left: 0 !important;
    margin-right: 0 !important;
    max-width: 100%;
  }
  .ol-body .topic-body,
  .ol-qbank > .q-bank-body,
  .ol-body .q-item .q-body {
    padding-left: 10px !important;
    padding-right: 10px !important;
  }
  .ol-body .q-head { padding-left: 8px; padding-right: 8px; }
  .ol-body .q-opts,
  .ol-body .q-stem,
  .ol-body .q-exp { overflow-wrap: anywhere; word-break: break-word; }
  .ol-body ul.steps,
  .ol-body ul.pits { padding-left: 18px; }
  .ol-body ul.feats { gap: 5px; }
}

@media (max-width: 400px) {
  .ol-body { padding-left: 8px !important; margin-left: 2px !important; }
  .topic-body { padding-left: 8px !important; padding-right: 8px !important; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}