/* finesse · register=product/工作台 · A=study-blue+cool-white · B=700/400-system-sans · C=white-rail+white-sheet
 * D=none-feedback-only · E=exam-web-app · SOUL=4 SPECTACLE=2 DENSITY=7 */
/* ==================================================================
   H.ai · AI 答疑 ·「学习蓝」
   工作台（桌面身体）—— 围着「他自己反复在做的一件事」转，不是后台
   底子  白侧栏 + 白顶栏 + 带蓝调的浅底 + 白卡；蓝只落在品牌 / 选中 / 按钮 / 标签上
   配色  主蓝 #3C7CFC · 青绿 #2BC8A0 · 红 #FF5A5A · 橙 #F39402
         文字 #222 / #3c464f · 分隔线 #F2F2F5 · 边框 #DDE0E5 · 底色 #F5F7FA
   语义  绿 = 答对 · 红 = 答错 · 橙 = 收藏 · 蓝 = 品牌 / 当前 / 考试模式已选
   ================================================================== */

:root {
  /* ── 底子：蓝调的冷白 ─────────────────────────────── */
  --page: #edf2fa;          /* 页面 = 浅蓝底 */
  --bg: #ffffff;            /* 卡片 = 白 */
  --panel-2: #f4f7fc;       /* 内嵌：题号槽 · 表头 · 输入 · 答题卡格 */
  --panel-3: #e4ebf6;       /* 更深一档的内嵌：进度槽 */
  --border: rgba(36, 61, 110, .10);
  --border-2: rgba(36, 61, 110, .17);

  --ink-1: #1f2530;         /* 标题 · 大数字 */
  --ink-2: #3c464f;         /* 正文 · 题干 */
  --ink-3: #667085;         /* 标签 · 说明 · 占位（--page 上 4.6:1，--bg 上 4.9:1） */
  --ink-4: #a3adbf;         /* 只给纯装饰用（图标、点、箭头），不承载文字 */

  /* ── 品牌 = 学习蓝 ─────────────────────────────────── */
  --accent: #3c7cfc;
  --accent-h: #2f6be6;
  --accent-soft: rgba(60, 124, 252, .10);
  --accent-line: rgba(60, 124, 252, .38);
  --on-accent: #ffffff;

  /* ── 语义三色（一律配图标或文字，不单独用色）────────── */
  --ok: #1a9e7e;   --ok-soft: rgba(43, 200, 160, .13);  --ok-line: rgba(43, 200, 160, .55);
  --bad: #f04747;  --bad-soft: rgba(255, 90, 90, .09);   --bad-line: rgba(255, 90, 90, .45);
  --fav: #f39402;  --fav-soft: rgba(243, 148, 2, .13);
  --fav-text: #c2700a;      /* 收藏做文字时的深一档 */
  --on-fill: #ffffff;       /* 压在 ok / bad 实心块上的字 */
  --bad-deep: #d93636;      /* 危险按钮悬停 */
  --mark: #fff2ad;          /* 检索命中高亮 */
  --rail-ok: #1a9e7e;       /* 侧栏里的「已完成」绿 */

  /* ── 左轨：白侧栏，选中项浅蓝底蓝字 ─────────────────── */
  --rail: #ffffff;
  --rail-2: #f4f7fc;                       /* 悬停面 */
  --rail-3: rgba(60, 124, 252, .10);       /* 选中面 */
  --rail-ink: #3c464f;
  --rail-ink-2: #7c869a;                   /* 轨内次级文字 / 占位 */
  --rail-ink-on: #2f6be6;                  /* 品牌名 · 选中 / 悬停文字 · 选中条 */
  --rail-border: rgba(36, 61, 110, .10);

  /* ── 布局 ────────────────────────────────────────── */
  --rail-w: 264px;
  --ai-w: 388px;
  --topbar-h: 60px;
  --content-w: 780px;       /* 中文 16px 下约 34 字一行，长材料读起来不累 */

  /* ── 圆角 / 阴影（阴影朝冷蓝偏，绝不用纯黑）──────────── */
  --r: 16px; --r-sm: 11px; --r-lg: 28px; --pill: 999px;
  --shadow: 0 1px 3px rgba(31, 45, 80, .06);
  --shadow-md: 0 6px 20px -10px rgba(31, 45, 80, .30);
  --shadow-lg: 0 30px 70px -46px rgba(31, 45, 80, .5);
  --ring: 0 0 0 3px rgba(60, 124, 252, .22);

  --z-sticky: 10; --z-sheet: 20; --z-fab: 30; --z-backdrop: 35; --z-panel: 40; --z-topbar: 50; --z-toast: 110;
  --dur-fast: 120ms; --dur: 180ms; --dur-slow: 260ms;
  --ease: cubic-bezier(.22, .9, .28, 1);

  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Segoe UI", "Hiragino Sans GB",
          "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", "Cascadia Mono", Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}

/* ---------------------------------------------------------------- 基础 */
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--page); color: var(--ink-2); font-family: var(--sans); font-size: 14px; line-height: 1.6;
  overflow: hidden; -webkit-font-smoothing: antialiased;
}
a { color: var(--ink-1); text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; }
button:disabled { cursor: not-allowed; }
img { max-width: 100%; height: auto; vertical-align: middle; }
kbd { font: inherit; font-family: var(--mono); font-size: 11px; padding: 1px 5px; border: 1px solid var(--border-2); border-bottom-width: 2px; border-radius: 4px; background: var(--bg); color: var(--ink-3); }
mark { background: var(--mark); color: inherit; padding: 0 1px; border-radius: 2px; }
::selection { background: rgba(60, 124, 252, .22); }
.topbar-meta, .stat-num, .pager-info, .paper-progress-text, .timer { font-variant-numeric: tabular-nums; }
.muted { color: var(--ink-3); }
.error { color: var(--bad); }
.ok { color: var(--ok); }
.spacer { flex: 1; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 3px; }
.input:focus-visible, .select:focus-visible, textarea:focus-visible { outline: 0; }
.ico { width: 1em; height: 1em; stroke: currentColor; fill: none; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; flex: none; vertical-align: -.16em; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.skip-link { position: absolute; left: 12px; top: -48px; z-index: 200; padding: 8px 14px; background: var(--accent); color: var(--on-accent); border-radius: var(--r-sm); font-size: 13px; transition: top var(--dur) var(--ease); }
.skip-link:focus { top: 8px; outline-color: var(--on-accent); }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}

/* ---------------------------------------------------------------- 骨架：轨 | 主 | AI */
/* overflow-x:clip 而不是 hidden —— hidden 会造出滚动容器，把里面的 sticky 全废掉 */
.app { display: flex; height: 100dvh; overflow-x: clip; }
/* 中栏按「自己有多宽」响应，而不是按视口。两侧面板一开，1440 的屏这里也只剩 788 */
.stack { flex: 1; min-width: 0; display: flex; flex-direction: column; container-type: inline-size; }
.main { flex: 1; min-width: 0; overflow-y: auto; display: flex; flex-direction: column; scroll-padding-top: 12px; scroll-padding-bottom: 140px; }
.content { width: 100%; max-width: var(--content-w); margin: 0 auto; padding: 22px 20px 84px; flex: 1 0 auto; outline: 0; }
.backdrop { position: fixed; inset: 0; background: rgba(20, 40, 90, .42); z-index: var(--z-backdrop); opacity: 0; pointer-events: none; transition: opacity var(--dur) var(--ease); }

/* ── 左轨（白侧栏，右侧一条细线与页面分开；用 inset 阴影而不是 border，收起到 0 宽时不会留一道线）── */
.rail {
  width: var(--rail-w); flex: 0 0 auto; background: var(--rail); color: var(--rail-ink); box-shadow: inset -1px 0 0 var(--border);
  display: flex; flex-direction: column; min-height: 0; transition: width var(--dur) var(--ease);
}
body.sidebar-collapsed .rail { width: 0; overflow: hidden; }
.rail-head { height: var(--topbar-h); flex: none; display: flex; align-items: center; padding: 0 14px; border-bottom: 1px solid var(--rail-border); }
.brand { display: flex; align-items: center; gap: 10px; height: 42px; padding: 0 8px 0 4px; border: 0; border-radius: var(--r-sm); background: transparent; white-space: nowrap; min-width: 0; transition: background var(--dur-fast) var(--ease); }
.brand:hover { background: var(--rail-2); }
.brand-mark { width: 30px; height: 30px; border-radius: 9px; background: var(--rail-ink-on); color: var(--rail); display: grid; place-items: center; flex: none; }
.brand-mark .ico { width: 17px; height: 17px; stroke-width: 2; }
.brand-text { display: flex; flex-direction: column; align-items: flex-start; min-width: 0; }
.brand-name { font-size: 15px; font-weight: 700; color: var(--rail-ink-on); letter-spacing: .02em; line-height: 1.25; }
.brand-sub { font-size: 11px; color: var(--rail-ink-2); line-height: 1.3; }
.rail-search { padding: 12px 12px 8px; flex: none; }
.rail .field-search > .ico { color: var(--rail-ink-2); }
.rail .field-search .input {
  background: var(--rail-2); border-color: transparent; color: var(--ink-1); border-radius: var(--pill); height: 34px; min-height: 34px; font-size: 13px;
}
.rail .field-search .input::placeholder { color: var(--rail-ink-2); }
.rail .field-search .input:focus { background: var(--bg); border-color: var(--accent); box-shadow: var(--ring); }

.tree { flex: 1; overflow-y: auto; padding: 2px 10px 24px; font-size: 13.5px; }
.tree-skeleton { padding: 8px 6px; }
.tree-empty { padding: 12px 12px; color: var(--rail-ink-2); font-size: 12.5px; }
.tree-group + .tree-group { margin-top: 4px; }
.tree-group-head, .tree-region-head { display: flex; align-items: center; gap: 7px; padding: 8px 10px; border-radius: var(--r-sm); cursor: pointer; user-select: none; transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease); }
.tree-group-head { font-weight: 600; color: var(--ink-1); font-size: 14px; }
.tree-group-head .grp { width: 16px; height: 16px; color: var(--accent); }
.tree-group-head:hover, .tree-region-head:hover { background: var(--rail-2); }
.tree-region-head { padding-left: 28px; color: var(--rail-ink); }
.tree-region-head:hover { color: var(--rail-ink-on); }
.tree-count { margin-left: auto; color: var(--rail-ink-2); font-size: 11px; font-weight: 400; font-variant-numeric: tabular-nums; white-space: nowrap; }
.caret { width: 13px; height: 13px; color: var(--rail-ink-2); transition: transform var(--dur) var(--ease); }
.open > .tree-group-head .caret, .open > .tree-region-head .caret { transform: rotate(90deg); }
.tree-regions, .tree-papers { display: none; }
.open > .tree-regions, .open > .tree-papers { display: block; }
.tree-papers { margin: 1px 0 6px 22px; padding-left: 10px; border-left: 1px solid var(--rail-border); }
.tree-paper { display: flex; align-items: center; gap: 8px; padding: 7px 10px; border-radius: var(--r-sm); color: var(--rail-ink); font-size: 13px; position: relative; transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease); }
.tree-paper:hover { background: var(--rail-2); color: var(--rail-ink-on); }
.tree-paper.active { background: var(--rail-3); color: var(--rail-ink-on); font-weight: 600; }
.tree-paper.active::before { content: ""; position: absolute; left: -11px; top: 8px; bottom: 8px; width: 2px; border-radius: 2px; background: var(--rail-ink-on); }
.tree-paper-name { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tree-paper-meta { color: var(--rail-ink-2); font-size: 11px; display: inline-flex; align-items: center; gap: 5px; white-space: nowrap; font-variant-numeric: tabular-nums; font-weight: 400; }
.tree-paper.active .tree-paper-meta { color: var(--rail-ink-on); }
.tree-paper-meta .done-ico { width: 13px; height: 13px; color: var(--rail-ok); }
.prog { width: 26px; height: 3px; border-radius: 2px; background: var(--panel-3); position: relative; display: inline-block; overflow: hidden; }
.prog::after { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: var(--pct); background: var(--rail-ok); border-radius: 2px; }

/* ── 顶栏（白，压在浅蓝底上）─────────────────────────── */
.topbar {
  height: var(--topbar-h); flex: none; background: var(--bg); border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 10px; padding: 0 18px 0 12px; position: relative; z-index: var(--z-topbar);
}
.topbar-left { display: flex; align-items: center; gap: 4px; min-width: 0; flex: 1 1 auto; overflow: hidden; }
/* 右侧动作不压缩（压缩只会让按钮互相重叠）；变窄由下面的容器查询逐级摘掉次要项 */
.topbar-right { display: flex; align-items: center; gap: 2px; flex: 0 0 auto; }
.topbar-right > * { flex: 0 0 auto; }
.topbar-center { min-width: 132px; flex: 1 1 0; overflow: hidden; margin-left: 8px; }
.topbar-title { font-size: 15px; font-weight: 600; color: var(--ink-1); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; line-height: 1.35; letter-spacing: -.005em; }
.topbar-meta { font-size: 12px; color: var(--ink-3); line-height: 1.35; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topbar-meta:empty { display: none; }
.topbar-meta b { color: var(--ink-1); font-weight: 600; }
.topbar-meta b.ok { color: var(--ok); }
.tb-sep { width: 1px; height: 20px; background: var(--border-2); margin: 0 6px; flex: none; }

.icon-btn {
  border: 0; background: transparent; border-radius: var(--r-sm); min-width: 34px; height: 34px; padding: 0 8px; font-size: 13px; color: var(--ink-3);
  display: inline-flex; align-items: center; justify-content: center; gap: 5px; white-space: nowrap;
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.icon-btn .ico { width: 18px; height: 18px; }
.icon-btn:hover { background: var(--accent-soft); color: var(--accent-h); }
.icon-btn:active { background: rgba(60, 124, 252, .16); }
body:not(.sidebar-collapsed) #btn-sidebar { color: var(--accent-h); }

.tb-btn {
  display: inline-flex; align-items: center; gap: 6px; height: 34px; border: 0; background: transparent; border-radius: var(--r-sm); padding: 0 11px;
  font-size: 13.5px; color: var(--ink-3); white-space: nowrap;
  transition: background var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.tb-btn .ico { width: 16px; height: 16px; }
.tb-btn:hover { background: var(--accent-soft); color: var(--accent-h); }
.tb-btn.on { background: var(--accent-soft); color: var(--accent-h); font-weight: 600; }
body:not(.ai-collapsed) #btn-ai-toggle { background: var(--accent-soft); color: var(--accent-h); font-weight: 600; }
.tb-btn.exam { background: var(--accent); color: var(--on-accent); font-weight: 600; }
.tb-btn.exam:hover { background: var(--accent-h); color: var(--on-accent); }
.tb-btn.primary { background: var(--accent); color: var(--on-accent); border-radius: var(--pill); padding: 0 16px; margin-left: 6px; font-weight: 600; }
.tb-btn.primary:hover { background: var(--accent-h); color: var(--on-accent); }

.top-search {
  display: flex; align-items: center; gap: 4px; background: var(--panel-2); border: 1px solid transparent; border-radius: var(--pill);
  padding: 0 3px 0 11px; height: 34px; min-width: 0; color: var(--ink-4);
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}
.top-search:focus-within { background: var(--bg); border-color: var(--accent-line); box-shadow: var(--ring); }
.top-search > .ico { width: 15px; height: 15px; }
.top-search input { border: 0; background: transparent; outline: 0; width: clamp(80px, 9vw, 150px); min-width: 0; font: inherit; font-size: 13.5px; color: var(--ink-1); }
.top-search input::placeholder { color: var(--ink-3); }
.top-search .icon-btn { min-width: 28px; height: 28px; padding: 0; border-radius: 50%; }
.top-search .icon-btn .ico { width: 15px; height: 15px; }

.timer { display: inline-flex; align-items: center; gap: 2px; background: var(--panel-2); border-radius: var(--pill); padding: 0 3px 0 11px; height: 34px; font-size: 13.5px; font-weight: 600; color: var(--ink-1); margin-right: 4px; }
.timer .clock { width: 14px; height: 14px; color: var(--ink-4); margin-right: 6px; }
.timer-text { font-family: var(--mono); font-size: 13px; letter-spacing: .01em; }
.timer.paused .timer-text { color: var(--ink-3); }
.timer-btn { border: 0; background: transparent; color: var(--ink-3); width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; padding: 0; margin-left: 2px; }
.timer-btn .ico { width: 11px; height: 11px; fill: currentColor; stroke: none; }
.timer-btn:hover { background: var(--bg); color: var(--ink-1); }

/* ---------------------------------------------------------------- 答题卡（底部抽屉，涂卡区质感） */
.sheet {
  position: sticky; bottom: 0; z-index: var(--z-sheet); flex: 0 0 auto; width: 100%; max-width: var(--content-w); margin: 0 auto;
  background: var(--bg); border-radius: var(--r) var(--r) 0 0; box-shadow: 0 -8px 26px -18px rgba(31, 45, 80, .45);
}
.sheet::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 1px; background: var(--border); border-radius: inherit; }
.sheet-head { display: flex; align-items: center; gap: 16px; padding: 0 24px; height: 46px; cursor: pointer; user-select: none; font-size: 13px; }
.sheet-title { font-weight: 600; font-size: 14px; color: var(--ink-1); display: inline-flex; align-items: center; gap: 8px; white-space: nowrap; }
.sheet-title .ico { width: 16px; height: 16px; color: var(--ink-3); }
.sheet-title b { font-variant-numeric: tabular-nums; }
.sheet-title .muted { font-weight: 400; }
.sheet-legend { display: inline-flex; align-items: center; gap: 12px; color: var(--ink-3); font-size: 12px; }
.sheet-legend .lg { display: inline-block; width: 11px; height: 11px; border-radius: 3px; background: var(--panel-2); border: 1px solid var(--border-2); margin-right: -8px; }
.sheet-legend .lg.ok { background: var(--ok-soft); border-color: var(--ok-line); }
.sheet-legend .lg.bad { background: var(--bad-soft); border-color: var(--bad-line); }
.sheet-legend .lg.pending { background: var(--accent); border-color: var(--accent); }
.sheet .link-btn { color: var(--ink-3); font-size: 13px; }
.sheet .link-btn:hover { color: var(--ink-1); background: transparent; }
.sheet-body { max-height: 264px; overflow-y: auto; padding: 4px 24px 18px; border-top: 1px solid var(--border); }
.sheet.collapsed .sheet-body { display: none; }
.sheet-sec { margin-top: 14px; }
.sheet-sec-title { font-size: 13px; font-weight: 600; color: var(--ink-2); margin-bottom: 9px; }
.sheet-sec-title .muted { font-weight: 400; font-size: 12px; }
.sheet-grid { display: flex; flex-wrap: wrap; gap: 8px; }
.num {
  width: 36px; height: 34px; border-radius: 9px; border: 1px solid var(--border-2); background: var(--panel-2); color: var(--ink-3);
  font-family: var(--mono); font-size: 13px; font-variant-numeric: tabular-nums; padding: 0; user-select: none;
  display: inline-flex; align-items: center; justify-content: center; position: relative;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
.num:hover { border-color: var(--accent); color: var(--accent-h); background: var(--bg); }
.num:active { transform: scale(.94); }
.num.pending { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.num.ok { background: var(--ok-soft); border-color: var(--ok-line); color: var(--ok); }
.num.bad { background: var(--bad-soft); border-color: var(--bad-line); color: var(--bad); }
.num.current { box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--accent); font-weight: 700; }
/* 对 / 错除颜色外再给一个角标，色弱也能分辨 */
.num.ok::before, .num.bad::before {
  content: ""; position: absolute; top: 3px; left: 4px; width: 7px; height: 7px; background: currentColor;
  -webkit-mask: var(--mk) center / contain no-repeat; mask: var(--mk) center / contain no-repeat;
}
.num.ok::before { --mk: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E"); }
.num.bad::before { --mk: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M18 6 6 18M6 6l12 12'/%3E%3C/svg%3E"); }
.num.fav::after { content: ""; position: absolute; top: 3px; right: 4px; width: 5px; height: 5px; border-radius: 50%; background: var(--fav); }

.fab-top {
  position: fixed; right: calc(var(--ai-w) + 22px); bottom: 74px; z-index: var(--z-fab); width: 38px; height: 38px; border-radius: 50%;
  border: 1px solid var(--border); background: var(--bg); color: var(--ink-3); display: grid; place-items: center; padding: 0; box-shadow: var(--shadow-md);
  transition: color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
.fab-top .ico { width: 17px; height: 17px; }
.fab-top:hover { color: var(--ink-1); transform: translateY(-1px); }
body.ai-collapsed .fab-top { right: 22px; }

/* ---------------------------------------------------------------- 通用组件 */
.card { background: var(--bg); border-radius: var(--r); padding: 22px 26px; margin-bottom: 16px; box-shadow: var(--shadow); }
.card-title { font-weight: 600; font-size: 15px; color: var(--ink-1); margin-bottom: 14px; display: flex; align-items: center; gap: 8px; }
.card-title .ico { width: 17px; height: 17px; color: var(--ink-3); }
.input, .select {
  border: 1px solid var(--border-2); border-radius: var(--r-sm); padding: 7px 12px; min-height: 36px; font: inherit; font-size: 13.5px; background: var(--bg); color: var(--ink-1); width: 100%;
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}
.input::placeholder { color: var(--ink-3); }
.input:focus, .select:focus { outline: 0; border-color: var(--accent); box-shadow: var(--ring); }
.select {
  width: auto; appearance: none; -webkit-appearance: none; padding-right: 30px; cursor: pointer;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23667085' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 10px center; background-size: 14px;
}
textarea.input { min-height: 0; line-height: 1.6; resize: vertical; }
.field-search { position: relative; display: flex; align-items: center; }
.field-search > .ico { position: absolute; left: 12px; width: 15px; height: 15px; color: var(--ink-4); pointer-events: none; }
.field-search .input { padding-left: 34px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 7px; border: 1px solid var(--border-2); background: var(--bg); border-radius: var(--pill);
  padding: 0 17px; height: 36px; font-size: 13.5px; color: var(--ink-2); white-space: nowrap;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease);
}
.btn .ico { width: 16px; height: 16px; }
.btn:hover { border-color: var(--accent); color: var(--accent-h); }
.btn:active { transform: scale(.98); }
.btn.disabled, .btn:disabled { opacity: .45; pointer-events: none; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-h); border-color: var(--accent-h); color: var(--on-accent); }
.btn-danger { background: var(--bad); border-color: var(--bad); color: var(--on-fill); }
.btn-danger:hover { background: var(--bad-deep); border-color: var(--bad-deep); color: var(--on-fill); }
.btn-ghost { border-color: transparent; background: transparent; color: var(--ink-3); }
.btn-ghost:hover { background: var(--accent-soft); border-color: transparent; color: var(--ink-1); }
.btn-sm { height: 31px; padding: 0 13px; font-size: 13px; }
.btn-sm .ico { width: 14px; height: 14px; }
.btn.loading { pointer-events: none; opacity: .75; }
.btn.loading::before { content: ""; width: 13px; height: 13px; border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; animation: spin .8s linear infinite; flex: none; }
.btn.loading .ico { display: none; }
@keyframes spin { to { transform: rotate(360deg); } }
.link-btn {
  border: 0; background: transparent; color: var(--ink-2); padding: 3px 7px; font-size: 13.5px; border-radius: 5px;
  display: inline-flex; align-items: center; gap: 5px; white-space: nowrap; transition: color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease);
}
.link-btn .ico { width: 14px; height: 14px; }
.link-btn:hover { color: var(--ink-1); background: var(--accent-soft); }
.link-btn:disabled { color: var(--ink-4); background: transparent; cursor: default; }
.loading { padding: 40px; text-align: center; color: var(--ink-3); }

.table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.table th, .table td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--border); color: var(--ink-2); font-variant-numeric: tabular-nums; }
.table th { color: var(--ink-3); font-weight: 400; font-size: 12.5px; }
.table td.n { text-align: right; font-family: var(--mono); }
.table th.n { text-align: right; }
.table tbody tr:last-child td { border-bottom: 0; }
.table .acc { display: flex; align-items: center; gap: 10px; min-width: 130px; }
.table .acc-bar { flex: 1; height: 5px; border-radius: 3px; background: var(--panel-3); position: relative; overflow: hidden; }
.table .acc-bar::after { content: ""; position: absolute; inset: 0 auto 0 0; width: var(--w); background: var(--ok); border-radius: 3px; }
.table .acc span { width: 38px; text-align: right; color: var(--ink-2); font-family: var(--mono); font-size: 12.5px; }

.skeleton { position: relative; overflow: hidden; background: var(--panel-3); border-radius: 5px; color: transparent; }
.rail .skeleton { background: var(--rail-2); }
.skeleton::after { content: ""; position: absolute; inset: 0; transform: translateX(-100%); background: linear-gradient(90deg, transparent, rgba(255, 255, 255, .65), transparent); animation: shimmer 1.4s infinite; }
@keyframes shimmer { to { transform: translateX(100%); } }
.sk-line { height: 11px; margin: 12px 0; }
.sk-title { height: 19px; width: 50%; margin: 2px 0 18px; }

.empty-state { text-align: center; padding: 52px 24px; color: var(--ink-3); }
.empty-state > .ico { width: 40px; height: 40px; stroke-width: 1.4; color: var(--ink-4); display: block; margin: 0 auto 14px; }
.empty-title { font-weight: 600; color: var(--ink-1); font-size: 15px; margin-bottom: 6px; }
.empty-actions { margin-top: 18px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

#toast {
  position: fixed; left: 50%; bottom: 40px; transform: translateX(-50%) translateY(14px); background: var(--accent); color: var(--on-accent);
  padding: 10px 18px; border-radius: var(--r-sm); font-size: 13.5px; opacity: 0; pointer-events: none; z-index: var(--z-toast);
  max-width: min(90vw, 480px); text-align: center; line-height: 1.5; box-shadow: var(--shadow-md);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------------------------------------------------------------- 试卷：一张浮在浅蓝底上的白卡 */
.paper { background: var(--bg); border-radius: var(--r); box-shadow: var(--shadow); padding: 0 30px 10px; margin-bottom: 16px; }
.paper-head { padding: 26px 0 20px; border-bottom: 1px solid var(--border); }
.paper-head-top { display: flex; align-items: flex-start; gap: 16px; }
.paper-title-wrap { flex: 1; min-width: 0; }
.paper-title { font-size: 21px; font-weight: 700; color: var(--ink-1); line-height: 1.45; letter-spacing: -.01em; margin: 0 0 10px; overflow-wrap: anywhere; text-wrap: balance; }
.paper-sub { display: flex; gap: 6px 16px; flex-wrap: wrap; align-items: center; color: var(--ink-3); font-size: 12.5px; }
.meta-chip { display: inline-flex; align-items: center; gap: 5px; white-space: nowrap; font-variant-numeric: tabular-nums; }
.meta-chip .ico { width: 13px; height: 13px; color: var(--ink-4); }
.paper-progress { margin-top: 18px; display: flex; align-items: center; gap: 16px; }
.pbar { flex: 1; height: 6px; border-radius: 3px; background: var(--panel-3); overflow: hidden; display: flex; }
.pbar i { display: block; height: 100%; transition: width var(--dur-slow) var(--ease); }
.pbar .ok { background: var(--ok); }
.pbar .bad { background: var(--bad); }
.pbar .pend { background: var(--accent); }
.paper-progress-text { font-size: 12.5px; color: var(--ink-3); white-space: nowrap; }
.paper-progress-text b { color: var(--ink-1); font-weight: 600; }
.paper-progress-text b.ok { color: var(--ok); }
.paper-progress-text b.bad { color: var(--bad); }
.paper-progress-text b.pend { color: var(--ink-1); }

/* 题型分区：一条蓝色短标，像卷子上的大题标题 */
.section-head { padding: 28px 0 2px; display: flex; align-items: baseline; gap: 12px; }
.section-title { font-size: 17px; font-weight: 700; color: var(--ink-1); line-height: 1.5; margin: 0; position: relative; padding-left: 14px; }
.section-title::before { content: ""; position: absolute; left: 0; top: .34em; width: 4px; height: .92em; border-radius: 2px; background: var(--accent); }
.section-count { color: var(--ink-3); font-weight: 400; font-size: 12.5px; margin-left: 8px; font-variant-numeric: tabular-nums; }
.section-desc { color: var(--ink-3); font-size: 12.5px; }

/* 材料：同组题共用，吸顶跟随 */
.mgroup { position: relative; }
.material { background: var(--panel-2); position: sticky; top: 0; z-index: var(--z-sticky); padding: 16px 20px 18px; margin: 22px 0 0; border-radius: var(--r-sm); box-shadow: 0 10px 22px -16px rgba(31, 45, 80, .45); }
.material-head { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; font-size: 12.5px; color: var(--ink-3); }
.material-tag { display: inline-flex; align-items: center; gap: 6px; color: var(--ink-1); font-weight: 600; font-size: 14px; }
.material-tag .ico { width: 15px; height: 15px; color: var(--ink-3); }
.material-head .link-btn { margin-left: auto; font-size: 12.5px; color: var(--ink-3); }
.material-body { font-size: 15.5px; line-height: 1.95; overflow: auto; max-height: 70vh; color: var(--ink-2); overflow-wrap: anywhere; }
.material.collapsible.collapsed .material-body { max-height: 32vh; }
.search-view .material, #s-results .material { position: static; box-shadow: none; }
.material-body p, .qstem p, .qanalysis-body p, .opt-text p { margin: 0 0 6px; }
.material-body p:last-child, .qstem p:last-child, .qanalysis-body p:last-child, .opt-text p:last-child { margin-bottom: 0; }
img.tex-img { display: inline; vertical-align: middle; max-height: 2.4em; width: auto; margin: 0 1px; }
img.tex-img.has-tex { cursor: copy; border-radius: 3px; }
img.tex-img.has-tex:hover { outline: 1px dashed var(--accent-line); background: var(--accent-soft); }
.qstem img:not(.tex-img), .material-body img:not(.tex-img), .qanalysis-body img:not(.tex-img) { display: block; margin: 9px 0; border-radius: 6px; }
.opt-text img:not(.tex-img) { display: inline-block; max-height: 220px; border-radius: 6px; }

/* 题目：题号在左沟槽（等宽数字，像印出来的卷子）
   content-visibility：一份行测卷 399 题、三万多个 DOM 节点、十八万像素高，全量排版光 layout 就要 150 ms+，
   低端手机上是几秒。加上这行后浏览器只对滚到附近的题卡做排版和绘制，屏幕外的直接跳过；
   contain-intrinsic-size 给个高度估值占位，量到真实高度后浏览器会记住（auto），滚动条不会乱跳。
   Ctrl+F 站内查找、锚点跳转、无障碍读屏都仍然能命中里面的内容。 */
.qcard {
  display: flex; gap: 14px; padding: 28px 0 20px; border-bottom: 1px solid var(--border); position: relative; scroll-margin-top: 12px;
  content-visibility: auto; contain-intrinsic-size: auto 260px;
}
/* 当前聚焦的那道题始终实时排版（右侧 AI 面板、键盘选项都指着它） */
.qcard.current { content-visibility: visible; }
.qcard:last-child { border-bottom: 0; }
.qcard.current::before { content: ""; position: absolute; left: -30px; top: 32px; width: 3px; height: 22px; border-radius: 0 3px 3px 0; background: var(--accent); }
.qno { flex: 0 0 40px; text-align: right; font-family: var(--mono); font-size: 15px; line-height: 30px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.qcard.current .qno, .qcard.answered .qno { color: var(--ink-2); }
.qbody { flex: 1; min-width: 0; }
.qtag { float: left; height: 22px; line-height: 22px; padding: 0 8px; border-radius: 5px; font-size: 12.5px; margin: 4px 9px 0 0; background: var(--accent-soft); color: var(--accent-h); white-space: nowrap; }
.kind-multi .qtag, .kind-judge .qtag, .kind-subjective .qtag { background: var(--accent-soft); color: var(--accent-h); }
.qstem { font-size: 16px; line-height: 1.9; color: var(--ink-1); word-break: break-word; overflow-wrap: anywhere; }
.qstem::after { content: ""; display: block; clear: both; }
.qstem u { text-decoration: underline; text-underline-offset: 3px; }

.options { display: flex; flex-direction: column; gap: 3px; margin-top: 14px; }
.opt { display: flex; align-items: flex-start; gap: 13px; padding: 7px 10px 7px 8px; margin-left: -8px; border-radius: var(--r-sm); cursor: pointer; position: relative; transition: background var(--dur-fast) var(--ease); }
.opt:hover { background: var(--panel-2); }
.opt:focus-visible { outline: 2px solid var(--accent); outline-offset: -1px; }
.opt-label {
  flex: 0 0 auto; width: 28px; height: 28px; border-radius: 50%; border: 1px solid var(--border-2); display: inline-flex; align-items: center; justify-content: center;
  font-size: 14px; color: var(--ink-3); background: var(--bg); margin-top: 2px;
  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.kind-multi .opt-label { border-radius: 7px; }
.opt:hover .opt-label { border-color: var(--accent); color: var(--accent-h); }
.opt-text { flex: 1; min-width: 0; font-size: 15.5px; line-height: 1.85; color: var(--ink-2); word-break: break-word; overflow-wrap: anywhere; }
.opt-mark { flex: none; width: 18px; height: 18px; margin-top: 7px; display: none; align-items: center; justify-content: center; }
.opt-mark .ico { width: 17px; height: 17px; stroke-width: 2.4; display: none; }
.opt.selected .opt-label { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.opt.correct { background: var(--ok-soft); }
.opt.correct .opt-label { background: var(--ok); border-color: var(--ok); color: var(--on-fill); }
.opt.correct .opt-text { color: var(--ink-1); }
.opt.correct .opt-mark { display: inline-flex; color: var(--ok); }
.opt.correct .opt-mark .mk-ok { display: block; }
.opt.wrong { background: var(--bad-soft); }
.opt.wrong .opt-label { background: var(--bad); border-color: var(--bad); color: var(--on-fill); }
.opt.wrong .opt-text { color: var(--ink-1); }
.opt.wrong .opt-mark { display: inline-flex; color: var(--bad); }
.opt.wrong .opt-mark .mk-bad { display: block; }
.qcard.answered .opt { cursor: default; }
.qcard.answered .opt:hover { background: transparent; }
.qcard.answered .opt.correct, .qcard.answered .opt.correct:hover { background: var(--ok-soft); }
.qcard.answered .opt.wrong, .qcard.answered .opt.wrong:hover { background: var(--bad-soft); }
.qcard.answered .opt:hover .opt-label { border-color: var(--border-2); color: var(--ink-3); }
.qcard.answered .opt.correct:hover .opt-label, .qcard.answered .opt.wrong:hover .opt-label { border-color: transparent; color: var(--on-fill); }

.qactions { display: flex; align-items: center; justify-content: flex-end; gap: 12px; margin-top: 14px; }
.qactions .hint { color: var(--ink-3); font-size: 12.5px; margin-right: auto; }

/* 题底一行：难度 / 来源在左，收藏 / 问 AI 在右 */
.qfoot { display: flex; align-items: center; gap: 14px; margin-top: 12px; font-size: 12.5px; color: var(--ink-3); min-height: 32px; }
.qsource { display: inline-flex; align-items: center; gap: 5px; color: var(--ink-3); min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.qsource .ico { width: 13px; height: 13px; }
.qsource:hover { color: var(--ink-1); }
/* 难度：正确率不只给数字，直接说它难不难（不靠颜色单独承载信息） */
.qdiff { display: inline-flex; align-items: center; gap: 7px; white-space: nowrap; }
.qdiff-dots { display: inline-flex; gap: 3px; }
.qdiff-dots i { width: 5px; height: 5px; border-radius: 50%; background: var(--panel-3); display: block; }
.qdiff-dots i.on { background: var(--ink-3); }
.qdiff.hard .qdiff-dots i.on { background: var(--bad); }
.qdiff.hard b { color: var(--bad); }
.qdiff b { font-weight: 600; color: var(--ink-2); }
.qdiff .rate-n { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.qtools { margin-left: auto; display: flex; align-items: center; gap: 2px; flex: none; }
.qtools .icon-btn { height: 30px; min-width: 30px; padding: 0 10px; font-size: 12.5px; color: var(--ink-3); }
.qtools .icon-btn .ico { width: 15px; height: 15px; }
.qtools .icon-btn:hover { color: var(--ink-1); background: var(--accent-soft); }
.qtools .icon-btn.fav.on { color: var(--fav-text); }
.qtools .icon-btn.fav.on .ico { fill: var(--fav); stroke: var(--fav-text); }
.qtools .icon-btn.fav.on:hover { background: var(--fav-soft); }
.chat-badge { background: var(--accent); color: var(--on-accent); font-size: 10px; font-weight: 600; border-radius: 8px; padding: 0 5px; line-height: 15px; min-width: 15px; text-align: center; font-family: var(--mono); }

/* 作答结果 + 解析：一块浅蓝灰区 */
.solu { display: none; margin-top: 16px; background: var(--panel-2); border-radius: var(--r-sm); padding: 15px 18px; }
.qcard.answered .solu, .qcard.show-analysis .solu, .qcard.force-analysis .solu { display: block; }
.qresult { display: none; align-items: center; gap: 8px 20px; flex-wrap: wrap; font-size: 13.5px; color: var(--ink-3); animation: rise var(--dur-slow) var(--ease); }
.qresult.show { display: flex; }
@keyframes rise { from { opacity: 0; transform: translateY(4px); } }
.qresult .ans, .qresult .mine { font-family: var(--mono); font-size: 19px; font-weight: 700; margin-left: 5px; vertical-align: -1px; }
.qresult .ans { color: var(--ok); }
.qresult .mine { color: var(--bad); }
.res-badge { display: inline-flex; align-items: center; gap: 5px; font-weight: 600; padding: 0 11px 0 9px; height: 26px; border-radius: var(--pill); font-size: 12.5px; }
.res-badge .ico { width: 14px; height: 14px; stroke-width: 2.4; }
.res-badge.ok { background: var(--ok-soft); color: var(--ok); }
.res-badge.bad { background: var(--bad-soft); color: var(--bad); }
.res-badge.none { background: var(--panel-3); color: var(--ink-3); }
/* 已交卷但没答的题：只看答案解析，选项不可点；答案行由结果条显示，解析里的那一行不重复 */
.qcard.locked .opt { cursor: default; }
.qcard.locked .opt:hover { background: transparent; }
.qcard.locked .opt:hover .opt-label { border-color: var(--border-2); color: var(--ink-3); }
.qcard.locked .opt.correct, .qcard.locked .opt.correct:hover { background: var(--ok-soft); }
.qcard.locked .opt.correct:hover .opt-label { border-color: transparent; color: var(--on-fill); }
.qcard.locked .qanalysis-answer { display: none; }
.timer.frozen .timer-text { color: var(--accent-h); }
.timer.frozen .timer-btn { color: var(--accent-h); cursor: default; }
.timer.frozen .timer-btn .ico { fill: none; stroke: currentColor; stroke-width: 2.2; }

/* ---------------------------------------------------------------- 考试情况（交卷后的报告卡） */
.exam-report { margin-top: 18px; border-left: 4px solid var(--accent); }
.report-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
.report-head .card-title { margin-bottom: 0; }
.report-when { display: inline-flex; align-items: center; gap: 5px; font-size: 12.5px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.report-when .ico { width: 13px; height: 13px; color: var(--ink-4); }
.report-sum { display: flex; flex-wrap: wrap; gap: 8px 22px; margin: 14px 0 6px; padding: 12px 16px; background: var(--panel-2); border-radius: var(--r-sm); font-size: 13.5px; color: var(--ink-3); }
.report-sum .rs { display: inline-flex; align-items: center; gap: 5px; white-space: nowrap; }
.report-sum .rs b { font-family: var(--mono); font-size: 17px; font-weight: 700; color: var(--ink-1); font-variant-numeric: tabular-nums; }
.report-sum .rs.ok b { color: var(--ok); }
.report-sum .rs.bad b { color: var(--bad); }
.report-sum .rs.nograde b { color: var(--ink-3); }
.report-sum .rs.rate b { color: var(--accent-h); }
.report-sum .rs.time .ico { width: 14px; height: 14px; color: var(--ink-4); }
.report-table td.mod { color: var(--ink-1); font-weight: 600; }
.report-table td .ok { color: var(--ok); font-weight: 600; }
.report-table td .bad { color: var(--bad); font-weight: 600; }
.report-table td.mono { font-family: var(--mono); font-size: 12.5px; white-space: nowrap; }
.report-table td.muted { color: var(--ink-3); }
.report-foot { display: flex; align-items: flex-start; gap: 6px; margin-top: 12px; font-size: 12px; color: var(--ink-3); line-height: 1.6; }
.report-foot .ico { width: 13px; height: 13px; flex: none; margin-top: 3px; color: var(--ink-4); }
@media (max-width: 640px) {
  .report-table th:nth-child(5), .report-table td:nth-child(5) { display: none; }   /* 窄屏先让掉「未答」列 */
  .report-sum { gap: 8px 14px; }
}
.qresult .rate { font-family: var(--mono); font-size: 12.5px; font-variant-numeric: tabular-nums; }
.solu-actions { margin-left: auto; display: inline-flex; align-items: center; gap: 2px; white-space: nowrap; }
.qresult .link-btn { font-size: 13px; padding: 3px 8px; color: var(--ink-3); }
.qresult .link-btn:hover { color: var(--ink-1); }
.qresult .link-btn.hi { color: var(--ink-1); font-weight: 500; }

.qanalysis { display: none; }
.qcard.show-analysis .qanalysis, .qcard.force-analysis .qanalysis { display: block; }
.qresult.show + .qanalysis { margin-top: 14px; padding-top: 15px; border-top: 1px solid var(--border-2); }
.qanalysis-title { display: flex; align-items: center; gap: 6px; font-size: 13px; font-weight: 600; color: var(--ink-1); margin-bottom: 7px; }
.qanalysis-title .ico { width: 14px; height: 14px; color: var(--ink-3); }
.qanalysis-body { color: var(--ink-2); line-height: 1.95; font-size: 14.5px; overflow-wrap: anywhere; }
.ref-answer { margin-bottom: 14px; }
.qanalysis-answer { font-size: 13.5px; margin-bottom: 12px; color: var(--ink-3); }
.qanalysis-answer b { color: var(--ok); font-family: var(--mono); font-size: 19px; font-weight: 700; margin: 0 5px; }
.qcard.answered .qanalysis-answer { display: none; }

/* 多版本解析页签条（analysis.js）：原解析 / AI 解析（analysis_ai）/ 各技能包版本 / 更多版本 / 生成；右侧 👍👎 / 重新生成 / 设为默认 */
.ana-badge { padding: 0 5px; border-radius: 4px; font-size: 11px; font-weight: 700; font-style: normal; letter-spacing: .02em; line-height: 17px; color: var(--accent-h); background: var(--accent-soft); }
.ana-tabs { position: relative; display: flex; flex-wrap: wrap; align-items: center; gap: 4px 6px; margin-bottom: 10px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
.ana-tab {
  border: 1px solid var(--border-2); background: var(--bg); color: var(--ink-2); padding: 3px 10px; font-size: 12.5px; line-height: 20px; border-radius: var(--pill);
  display: inline-flex; align-items: center; gap: 5px; white-space: nowrap; max-width: 220px; overflow: hidden; text-overflow: ellipsis;
  transition: color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.ana-tab .ico { width: 13px; height: 13px; flex: none; }
.ana-tab:hover { color: var(--ink-1); background: var(--panel-2); border-color: var(--accent-line); }
.ana-tab.on { color: var(--accent-h); background: var(--accent-soft); border-color: var(--accent-line); font-weight: 600; }
.ana-tab.on .ana-badge { background: var(--bg); }
.ana-tab.busy { border-style: dashed; }
.ana-tab.gen { color: var(--ink-3); border-style: dashed; }
.ana-tab.gen:hover { color: var(--accent-h); }
.ana-tab.gen.off { color: var(--ink-4, #a3adbf); cursor: help; opacity: .8; }   /* 我的技能包不覆盖这类题：标灰，悬停看原因 */
.ana-tab.gen.off:hover { color: var(--ink-3); }
.ana-menu-item.off, .ana-menu-item:disabled { color: var(--ink-4, #a3adbf); cursor: not-allowed; }
.ana-menu-item.off:hover { background: transparent; color: var(--ink-4, #a3adbf); }
.ana-tab.more { color: var(--ink-3); }
.ana-tab-wrap { position: relative; display: inline-flex; align-items: center; }
.ana-tab-wrap .ana-tab { border-top-right-radius: 0; border-bottom-right-radius: 0; border-right: 0; padding-right: 8px; }
.ana-tab-wrap .ana-tab.more { border-radius: var(--pill); border-right: 1px solid var(--border-2); padding-right: 10px; }
.ana-caret {
  border: 1px solid var(--border-2); background: var(--bg); color: var(--ink-3); padding: 3px 5px 3px 4px; line-height: 20px; height: 28px;
  border-top-right-radius: var(--pill); border-bottom-right-radius: var(--pill); display: inline-flex; align-items: center;
}
.ana-caret .ico { width: 13px; height: 13px; }
.ana-caret:hover { color: var(--accent-h); background: var(--panel-2); }
.ana-tab-wrap:has(.ana-tab.on) .ana-caret { border-color: var(--accent-line); color: var(--accent-h); background: var(--accent-soft); }
.ana-gen-locked { border: 0; background: transparent; color: var(--ink-3); font-size: 12.5px; display: inline-flex; align-items: center; gap: 4px; padding: 3px 6px; border-radius: var(--pill); }
.ana-gen-locked .ico { width: 13px; height: 13px; color: var(--fav); }
.ana-gen-locked:hover { background: var(--fav-soft); color: var(--fav-text); }
.ana-tools { margin-left: auto; display: inline-flex; align-items: center; gap: 2px; }
.ana-tools .link-btn { font-size: 12.5px; padding: 2px 7px; color: var(--ink-3); }
.ana-tools .link-btn:hover { color: var(--ink-1); }
.ana-fb { border: 0; background: transparent; color: var(--ink-3); font-size: 12.5px; padding: 2px 7px; border-radius: var(--pill); display: inline-flex; align-items: center; gap: 3px; }
.ana-fb b { font-weight: 500; font-variant-numeric: tabular-nums; }
.ana-fb:hover { background: var(--panel-2); color: var(--ink-1); }
.ana-fb.on { color: var(--accent-h); background: var(--accent-soft); }
.ana-menu {
  position: absolute; top: 100%; left: 0; z-index: var(--z-sticky); margin-top: 4px; min-width: 190px; max-width: 320px; padding: 4px;
  background: var(--bg); border: 1px solid var(--border-2); border-radius: var(--r-sm); box-shadow: var(--shadow-md); display: flex; flex-direction: column;
}
.ana-menu-item { border: 0; background: transparent; text-align: left; font-size: 13px; color: var(--ink-2); padding: 6px 10px; border-radius: 7px; display: flex; align-items: center; gap: 6px; }
.ana-menu-item .ico { width: 13px; height: 13px; color: var(--ink-3); }
.ana-menu-item:hover { background: var(--panel-2); color: var(--ink-1); }
.ana-menu-item.on { color: var(--accent-h); background: var(--accent-soft); }
.ana-menu-empty { font-size: 12.5px; padding: 6px 10px; }
.ana-note { font-size: 12.5px; line-height: 1.6; color: var(--fav-text); background: var(--fav-soft); border-radius: 8px; padding: 6px 10px; margin-bottom: 10px; display: flex; flex-direction: column; gap: 2px; }
.ana-note .ico { width: 13px; height: 13px; vertical-align: -2px; margin-right: 4px; }
.ana-note b { font-weight: 600; }
.ana-note-link { color: var(--accent-h); text-decoration: underline; cursor: pointer; }
.ana-note-link:hover { color: var(--accent); }
.ana-status { font-size: 12.5px; color: var(--ink-3); display: flex; align-items: center; gap: 5px; margin-bottom: 8px; }
.ana-status .ico { width: 13px; height: 13px; }
.ico.spin { animation: spin 1s linear infinite; }   /* 流式生成时页签 / 状态行里的转圈（.cursor 光标复用聊天气泡那套） */
.qanalysis-body.md { font-size: 14px; line-height: 1.85; }
.qanalysis-body.md h1, .qanalysis-body.md h2, .qanalysis-body.md h3 { font-size: 14px; margin: 12px 0 5px; }
.qanalysis-body.md > :first-child { margin-top: 0; }

/* ---------------------------------------------------------------- 检索 */
.filterbar { padding: 20px 26px; }
.filter-row { display: flex; gap: 12px; align-items: flex-end; flex-wrap: wrap; }
.filter-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 12px; margin-top: 14px; }
.field { display: flex; flex-direction: column; gap: 6px; min-width: 0; flex: 1 1 140px; }
.field.grow { flex: 1 1 300px; }
.field > label { font-size: 12.5px; color: var(--ink-3); }
.field .select { width: 100%; }
.filter-row .field-search { flex: 1; }
.search-summary { color: var(--ink-3); margin: 4px 6px 12px; font-size: 13.5px; display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.search-summary b { color: var(--ink-1); font-variant-numeric: tabular-nums; }
.search-summary:empty { display: none; }
#s-results .paper { padding-top: 0; }
#s-results .qcard:first-child { padding-top: 24px; }
.pager { display: flex; justify-content: center; align-items: center; gap: 14px; padding: 16px; }
.pager-info { color: var(--ink-3); font-size: 13.5px; font-family: var(--mono); }

/* ---------------------------------------------------------------- 首页 */
.home-hero { padding: 30px 32px; position: relative; overflow: hidden; }
.home-hero::after { content: ""; position: absolute; right: -80px; top: -110px; width: 300px; height: 300px; border-radius: 50%; background: radial-gradient(closest-side, rgba(60, 124, 252, .10), transparent); pointer-events: none; }
.home-title { font-size: 26px; font-weight: 700; color: var(--ink-1); letter-spacing: -.02em; line-height: 1.25; margin: 0; display: flex; align-items: center; gap: 14px; }
.home-title .brand-mark { width: 42px; height: 42px; border-radius: 12px; background: var(--accent); color: var(--on-accent); }
.home-title .brand-mark .ico { width: 23px; height: 23px; }
.home-sub { color: var(--ink-3); margin: 12px 0 22px; font-size: 13.5px; }
.home-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.home-actions .btn { height: 38px; padding: 0 20px; }
.home-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-bottom: 16px; }
.stat { display: flex; align-items: center; gap: 15px; margin: 0; padding: 20px 22px; }
.stat-icon { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; flex: none; background: var(--panel-2); color: var(--ink-3); }
.stat-icon .ico { width: 20px; height: 20px; }
.stat-icon.green { background: var(--ok-soft); color: var(--ok); }
.stat-icon.amber { background: var(--fav-soft); color: var(--fav-text); }
.stat-num { font-size: 26px; font-weight: 700; color: var(--ink-1); line-height: 1.1; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.stat-label { color: var(--ink-3); font-size: 12.5px; margin-top: 4px; }
.tiles { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-bottom: 16px; }
.tile { display: flex; align-items: center; gap: 14px; padding: 17px 20px; min-width: 0; background: var(--bg); border-radius: var(--r); color: var(--ink-1); box-shadow: var(--shadow); transition: transform var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease); }
.tile:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.tile-icon { width: 40px; height: 40px; border-radius: 11px; display: grid; place-items: center; flex: none; background: var(--panel-2); color: var(--ink-3); }
.tile-icon .ico { width: 19px; height: 19px; }
.tile-icon.red { background: var(--bad-soft); color: var(--bad); }
.tile-icon.amber { background: var(--fav-soft); color: var(--fav-text); }
.tile-text { min-width: 0; display: flex; flex-direction: column; }
.tile-name { font-weight: 600; font-size: 14.5px; line-height: 1.3; white-space: nowrap; }
.tile-desc { font-size: 12.5px; color: var(--ink-3); margin-top: 3px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tile > .arrow { margin-left: auto; color: var(--ink-4); width: 16px; height: 16px; transition: transform var(--dur-fast) var(--ease); }
.tile:hover > .arrow { transform: translateX(2px); color: var(--ink-2); }
.home-tip ol { margin: 0; padding: 0; list-style: none; counter-reset: step; display: grid; gap: 12px; }
.home-tip li { counter-increment: step; display: grid; grid-template-columns: 23px minmax(0, 1fr); gap: 12px; color: var(--ink-2); line-height: 1.85; font-size: 13.5px; }
.home-tip li::before { content: counter(step); width: 23px; height: 23px; border-radius: 50%; background: var(--accent); color: var(--on-accent); font-family: var(--mono); font-weight: 600; font-size: 11.5px; display: grid; place-items: center; margin-top: 4px; }
.home-tip li > span { min-width: 0; }

/* ---------------------------------------------------------------- AI 面板 */
.aipanel { width: var(--ai-w); flex: 0 0 auto; background: var(--bg); border-left: 1px solid var(--border); display: flex; flex-direction: column; min-height: 0; transition: width var(--dur) var(--ease); }
body.ai-collapsed .aipanel { width: 0; overflow: hidden; border-left: 0; }
.ai-head { display: flex; align-items: center; gap: 10px; padding: 0 12px 0 18px; border-bottom: 1px solid var(--border); height: var(--topbar-h); flex: none; }
.ai-title { font-weight: 600; font-size: 15px; color: var(--ink-1); display: flex; align-items: center; gap: 9px; white-space: nowrap; }
.ai-logo { width: 27px; height: 27px; border-radius: 8px; background: var(--accent); color: var(--on-accent); display: grid; place-items: center; flex: none; }
.ai-logo .ico { width: 15px; height: 15px; }
.ai-model {
  flex: 1; min-width: 0; max-width: 180px; font-size: 12px; color: var(--ink-3); background: var(--panel-2); padding: 5px 26px 5px 10px; border-radius: var(--pill);
  border: 1px solid transparent; font-family: inherit; cursor: pointer; appearance: none; -webkit-appearance: none; text-overflow: ellipsis;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a3adbf' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 9px center; background-size: 12px;
}
.ai-model:hover { color: var(--ink-1); }
.ai-model:focus { outline: 0; border-color: var(--accent); box-shadow: var(--ring); background-color: var(--bg); }
.ai-actions { margin-left: auto; display: flex; gap: 2px; }
#btn-ai-settings { display: none; }
.ai-context { padding: 12px 18px; border-bottom: 1px solid var(--border); font-size: 12.5px; background: var(--panel-2); }
.ctx-none { color: var(--ink-3); display: inline-flex; align-items: center; gap: 6px; }
.ctx-none .ico { width: 14px; height: 14px; color: var(--ink-4); }
.ctx-hint { color: var(--ink-3); margin-left: 6px; }
.ctx-main { display: flex; align-items: center; gap: 9px; }
.ctx-badge { background: var(--accent); color: var(--on-accent); border-radius: 5px; padding: 0 8px; height: 22px; line-height: 22px; font-size: 12.5px; font-weight: 600; white-space: nowrap; }
.ctx-kind { color: var(--ink-3); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ctx-goto { margin-left: auto; font-size: 12.5px; cursor: pointer; flex: none; color: var(--ink-3); }
.ctx-stem { color: var(--ink-3); margin-top: 6px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ctx-formula { color: var(--ink-3); margin-top: 5px; display: flex; align-items: center; gap: 5px; font-size: 12px; }
.ctx-formula .ico { width: 13px; height: 13px; }
.ctx-formula b { color: var(--ink-1); font-weight: 600; font-family: var(--mono); }
.ctx-formula .link-btn { font-size: 12px; padding: 1px 5px; }
.ai-messages { flex: 1; overflow-y: auto; padding: 18px; background: var(--bg); }
.ai-empty { color: var(--ink-3); text-align: center; padding: 52px 20px; font-size: 13px; line-height: 1.9; }
.ai-empty > .ico { width: 38px; height: 38px; color: var(--ink-4); display: block; margin: 0 auto 12px; stroke-width: 1.4; }
.msg { margin-bottom: 18px; display: flex; gap: 10px; align-items: flex-start; }
.msg.user { justify-content: flex-end; }
.msg .avatar { width: 27px; height: 27px; border-radius: 50%; background: var(--accent-soft); color: var(--ink-2); display: grid; place-items: center; flex: none; margin-top: 3px; }
.msg .avatar .ico { width: 14px; height: 14px; }
.msg-body { min-width: 0; flex: 1; }
.msg.user .msg-body { flex: 0 1 auto; max-width: 85%; }
.bubble { padding: 11px 14px; border-radius: 13px; font-size: 13.5px; line-height: 1.8; word-break: break-word; overflow-wrap: anywhere; }
.msg.user .bubble { background: var(--accent); color: var(--on-accent); border-top-right-radius: 4px; }
.msg.assistant .bubble { background: var(--panel-2); color: var(--ink-2); border-top-left-radius: 4px; }
.msg-tools { display: flex; gap: 2px; margin-top: 4px; opacity: 0; transition: opacity var(--dur-fast) var(--ease); }
.msg:hover .msg-tools, .msg:focus-within .msg-tools { opacity: 1; }
.msg-tools .link-btn { font-size: 12px; color: var(--ink-3); padding: 2px 7px; }
.msg-tools .link-btn:hover { color: var(--ink-1); }
.typing { color: var(--ink-3); display: inline-flex; align-items: center; gap: 8px; }
.typing::before { content: ""; width: 5px; height: 5px; border-radius: 50%; background: var(--ink-2); margin-right: 18px; flex: none; box-shadow: 9px 0 0 var(--ink-4), 18px 0 0 var(--ink-4); animation: dots 1.1s infinite ease-in-out; }
@keyframes dots {
  0%, 100% { background: var(--ink-2); box-shadow: 9px 0 0 var(--ink-4), 18px 0 0 var(--ink-4); }
  33% { background: var(--ink-4); box-shadow: 9px 0 0 var(--ink-2), 18px 0 0 var(--ink-4); }
  66% { background: var(--ink-4); box-shadow: 9px 0 0 var(--ink-4), 18px 0 0 var(--ink-2); }
}
.cursor { display: inline-block; width: 7px; height: 14px; background: var(--ink-2); vertical-align: -2px; margin-left: 2px; border-radius: 1px; animation: blink 1s steps(2) infinite; }
@keyframes blink { to { opacity: 0; } }
.reasoning { margin-bottom: 8px; font-size: 12px; color: var(--ink-3); background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 6px 10px; }
.reasoning summary { cursor: pointer; }
.reasoning-body { margin-top: 6px; padding-left: 8px; border-left: 2px solid var(--border-2); max-height: 220px; overflow-y: auto; line-height: 1.6; }
.md p { margin: 0 0 8px; }
.md p:last-child { margin-bottom: 0; }
.md h1, .md h2, .md h3, .md h4 { font-size: 14px; margin: 12px 0 6px; line-height: 1.5; color: var(--ink-1); }
.md h1 { font-size: 16px; } .md h2 { font-size: 15px; }
.md ul, .md ol { margin: 4px 0 8px; padding-left: 22px; }
.md li { margin: 3px 0; }
.md code { background: var(--accent-soft); color: var(--ink-1); padding: 1px 6px; border-radius: 4px; font-size: 12.5px; font-family: var(--mono); }
.md pre { background: var(--bg); border: 1px solid var(--border); padding: 10px 12px; border-radius: 8px; overflow-x: auto; margin: 6px 0 10px; }
.md pre code { background: transparent; padding: 0; }
.md blockquote { margin: 6px 0; padding: 4px 10px; border-left: 3px solid var(--border-2); color: var(--ink-3); }
.md table { border-collapse: collapse; margin: 6px 0 10px; font-size: 12.5px; display: block; overflow-x: auto; max-width: 100%; }
.md th, .md td { border: 1px solid var(--border-2); padding: 4px 8px; }
.md th { background: var(--bg); }
.md hr { border: 0; border-top: 1px solid var(--border-2); margin: 10px 0; }
.md .math-block { overflow-x: auto; margin: 6px 0; }
.md strong { color: var(--ink-1); }
.msg.user .md strong { color: var(--on-accent); }
.msg.user .md code { color: var(--on-accent); background: rgba(255, 255, 255, .2); }
.ai-quick { display: flex; gap: 7px; flex-wrap: wrap; padding: 12px 18px 0; border-top: 1px solid var(--border); background: var(--bg); }
.ai-quick:empty { display: none; }
.chip { border: 1px solid var(--border-2); background: var(--bg); color: var(--ink-3); border-radius: var(--pill); padding: 5px 12px; font-size: 12.5px; line-height: 1.4; text-align: left; max-width: 100%; transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease); }
.chip:hover { border-color: var(--accent); color: var(--ink-1); background: var(--accent-soft); }
.chip:active { transform: scale(.97); }
.chip .ico { width: 13px; height: 13px; vertical-align: -2px; margin-right: 4px; }
/* 讲解层级：做成一个 chip 形状的下拉 */
.chip-select { position: relative; display: inline-flex; align-items: center; gap: 4px; padding: 0 8px 0 11px; cursor: pointer; }
.chip-select:active { transform: none; }
.chip-select-label { color: var(--ink-3); font-size: 12px; }
.chip-select select {
  appearance: none; -webkit-appearance: none; border: 0; background: transparent; color: var(--accent-h); font: inherit; font-size: 12.5px; font-weight: 600;
  padding: 5px 2px; cursor: pointer; max-width: 90px;
}
.chip-select select:focus { outline: 0; }
.chip-select:focus-within { border-color: var(--accent); box-shadow: var(--ring); }
.chip-select .caret { width: 13px; height: 13px; color: var(--ink-4); margin: 0; }
.chip-toggle.on, .chip-toggle[aria-expanded="true"] { border-color: var(--accent); color: var(--accent-h); background: var(--accent-soft); }
/* 「我卡在哪」展开的一行 */
.stuck-row { flex-basis: 100%; display: flex; align-items: center; gap: 6px; flex-wrap: wrap; padding: 8px 10px; border-radius: var(--r-sm); background: var(--panel-2); border: 1px dashed var(--border-2); }
.stuck-label { font-size: 12px; color: var(--ink-3); white-space: nowrap; }
.chip-stuck { padding: 4px 10px; font-size: 12px; background: var(--bg); }
.who-level { color: var(--accent-h); font-weight: 600; }
/* 复用的共享回答（没调模型） */
.who-cached { display: inline-flex; align-items: center; gap: 3px; color: var(--ok); font-weight: 600; cursor: help; }
.who-cached .ico { width: 12px; height: 12px; }
.set-cache-row { align-items: center; }
.set-cache-row .set-note { flex: 1; }
.ai-input { display: flex; gap: 10px; padding: 12px 18px 8px; background: var(--bg); align-items: flex-end; }
.ai-input textarea {
  flex: 1; resize: none; border: 1px solid var(--border-2); border-radius: var(--r-sm); padding: 10px 13px; font: inherit; font-size: 13.5px; line-height: 1.6;
  max-height: 160px; min-height: 42px; background: var(--bg); color: var(--ink-1);
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}
.ai-input textarea::placeholder { color: var(--ink-3); }
.ai-input textarea:focus { outline: 0; border-color: var(--accent); box-shadow: var(--ring); }
.ai-send { width: 42px; height: 42px; padding: 0; border-radius: 50%; flex: none; }
.ai-send .ico { width: 18px; height: 18px; }
.ai-foot { padding: 0 18px 12px; font-size: 11.5px; color: var(--ink-3); display: flex; align-items: center; gap: 5px; line-height: 1.5; flex-wrap: wrap; }
.ai-foot .ico { width: 12px; height: 12px; }

/* ---------------------------------------------------------------- 对话框 */
.dlg { border: 0; border-radius: var(--r-lg); padding: 0; width: 580px; max-width: 95vw; max-height: 92dvh; box-shadow: var(--shadow-lg), 0 2px 8px rgba(31, 45, 80, .1); color: var(--ink-2); background: var(--bg); }
.dlg::backdrop { background: rgba(20, 40, 90, .48); }
.dlg[open] { animation: dlg-in var(--dur-slow) var(--ease); }
@keyframes dlg-in { from { opacity: 0; transform: translateY(8px) scale(.985); } }
.dlg form { display: flex; flex-direction: column; max-height: 92dvh; }
.dlg-head { display: flex; align-items: center; gap: 10px; padding: 18px 14px 14px 26px; border-bottom: 1px solid var(--border); }
.dlg-head > .ico { width: 18px; height: 18px; color: var(--ink-3); }
.dlg h3 { margin: 0; font-size: 17px; font-weight: 700; color: var(--ink-1); }
.dlg-head .icon-btn { margin-left: auto; }
.dlg-body { padding: 4px 26px 6px; overflow-y: auto; }
.dlg fieldset { border: 0; padding: 15px 0 6px; margin: 0; border-bottom: 1px solid var(--border); min-width: 0; }
.dlg fieldset:last-child { border-bottom: 0; }
.dlg legend { padding: 0; font-size: 12.5px; font-weight: 700; color: var(--ink-1); margin-bottom: 10px; }
.dlg label { display: block; font-size: 13px; color: var(--ink-3); margin-bottom: 12px; }
.dlg label .input, .dlg label .select { margin-top: 6px; }
.dlg .help { display: block; font-size: 12px; color: var(--ink-3); margin-top: 4px; line-height: 1.55; }
.dlg .row { display: flex; gap: 10px; align-items: flex-start; }
.dlg .row > .input { flex: 1; min-width: 0; }
.dlg .row > .select { max-width: 40%; }
.dlg .row .btn { margin-top: 6px; flex: none; }
.dlg .half { flex: 1; min-width: 0; }
.dlg .half .select { width: 100%; }
.dlg .check { display: flex; align-items: flex-start; gap: 10px; color: var(--ink-1); font-size: 13.5px; padding: 8px 10px; margin: 0 -10px 4px; border-radius: var(--r-sm); cursor: pointer; transition: background var(--dur-fast) var(--ease); }
.dlg .check:hover { background: var(--panel-2); }
.dlg .check input { margin: 3px 0 0; width: 16px; height: 16px; accent-color: var(--accent); flex: none; cursor: pointer; }
.dlg .check .help { margin-top: 1px; }
.input-wrap { position: relative; display: flex; align-items: center; margin-top: 6px; }
.input-wrap .input { margin-top: 0 !important; padding-right: 40px; }
.input-wrap .icon-btn { position: absolute; right: 4px; width: 30px; min-width: 30px; height: 30px; color: var(--ink-3); }
.input-wrap .icon-btn .ico { width: 16px; height: 16px; }
.dlg .set-note.block { font-size: 12.5px; color: var(--ink-2); line-height: 1.55; padding: 9px 12px; background: var(--panel-2); border-radius: var(--r-sm); margin: 0 0 10px; display: flex; align-items: flex-start; gap: 7px; }
.dlg .set-note.block:empty { display: none; }
.dlg .set-note .ico { width: 14px; height: 14px; flex: none; margin-top: 2px; color: var(--ink-3); }
.dlg-foot { display: flex; align-items: center; gap: 10px; padding: 14px 26px 20px; border-top: 1px solid var(--border); }
.dlg-foot .muted { font-size: 12.5px; max-width: 280px; line-height: 1.45; }

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: rgba(36, 61, 110, .18); border-radius: 5px; border: 2px solid transparent; background-clip: padding-box; }
::-webkit-scrollbar-thumb:hover { background: rgba(36, 61, 110, .32); background-clip: padding-box; }

/* ---------------------------------------------------------------- 响应式 */

/* 顶栏拥挤度：按中栏自身宽度收缩，先收按钮文字，再收搜索框 */
@container (max-width: 940px) {
  /* 设置 / AI 面板 / 解析有明确图标，收起文字；但「练习模式 vs 考试模式」和「交卷」是状态和后果，文字必须留 */
  .tb-label { display: none; }
  #btn-mode .tb-label, #btn-submit .tb-label { display: inline; }
  .tb-btn { padding: 0 9px; }
  #btn-mode { padding: 0 11px; }
  .tb-btn.primary { padding: 0 13px; }
}
@container (max-width: 860px) { .top-search input { width: 74px; } }
@container (max-width: 760px) {
  .top-search { padding: 0; background: transparent; border: 0; }
  .top-search > .ico, .top-search input { display: none; }
  .top-search .icon-btn { min-width: 34px; height: 34px; border-radius: var(--r-sm); }
  .top-search .icon-btn .ico { width: 18px; height: 18px; }
  .timer .clock { display: none; }
  .timer { padding-left: 10px; }
}
/* 再窄：解析和设置让位（设置改从 AI 面板标题栏进） */
@container (max-width: 640px) {
  #btn-analysis, #btn-settings { display: none; }
  #btn-ai-settings { display: inline-flex; }
}
@container (max-width: 520px) { .tb-sep, #btn-back { display: none; } .topbar-center { min-width: 0; } }

@media (max-width: 1400px) { :root { --ai-w: 356px; --rail-w: 248px; } }
@media (max-width: 1023px) {
  .rail { position: fixed; left: 0; top: 0; bottom: 0; z-index: var(--z-panel); width: 0; overflow: hidden; }
  body.sidebar-open .rail { width: min(316px, 88vw); box-shadow: var(--shadow-lg); }
  .aipanel { position: fixed; right: 0; top: 0; bottom: 0; z-index: var(--z-panel); width: min(420px, 100vw); box-shadow: var(--shadow-lg); }
  body.ai-collapsed .aipanel { width: 0; box-shadow: none; }
  body.sidebar-open .backdrop, body:not(.ai-collapsed) .backdrop { opacity: 1; pointer-events: auto; }
  .fab-top, body.ai-collapsed .fab-top { right: 16px; }
  .sheet-legend { display: none; }
  .content { padding: 14px 14px 84px; }
}
@media (max-width: 767px) {
  .topbar { gap: 6px; padding: 0 8px; }
  .topbar-center { margin-left: 4px; }
  .topbar-title { font-size: 14px; }
  .card, .home-hero { padding: 18px; }
  .paper { padding: 0 16px 8px; }
  .paper-head { padding: 20px 0 16px; }
  .paper-head-top { flex-direction: column; align-items: flex-start; gap: 10px; }
  .paper-title { font-size: 18px; }
  .paper-progress { margin-top: 14px; flex-direction: column; align-items: stretch; gap: 8px; }
  .paper-progress-text { white-space: normal; }
  .qcard { gap: 9px; padding: 22px 0 16px; }
  .qcard.current::before { left: -16px; }
  .qno { flex: 0 0 26px; font-size: 14px; }
  .qstem { font-size: 16px; }
  .opt-text { font-size: 15.5px; }
  .material { padding: 14px 15px; margin-top: 18px; }
  .solu { padding: 13px 15px; }
  .num { width: 42px; height: 40px; }
  .sheet-head { padding: 0 16px; }
  .sheet-body { padding: 4px 16px 16px; max-height: 40vh; }
  .home-grid { grid-template-columns: 1fr; gap: 10px; }
  .stat { padding: 15px 16px; }
  .stat-icon { width: 38px; height: 38px; }
  .stat-num { font-size: 22px; }
  .home-title { font-size: 21px; }
  .qfoot { flex-wrap: wrap; }
  .dlg .row { flex-direction: column; gap: 0; }
  .dlg .row > .select { max-width: none; }
}
@media (max-width: 480px) { .tiles { grid-template-columns: 1fr; } }