/* ============ 基础变量 ============ */
:root{
  --bg:#f4f6fb;
  --card:#ffffff;
  --card2:#f8fafc;
  --text:#0f172a;
  --muted:#64748b;
  --line:rgba(15,23,42,.09);
  --accent:#6366f1;
  --accent-2:#8b5cf6;
  --green:#10b981;
  --red:#ef4444;
  --amber:#f59e0b;
  --shadow:0 1px 2px rgba(15,23,42,.04), 0 14px 34px -16px rgba(15,23,42,.22);
  --radius:16px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
}
[data-theme="dark"]{
  --bg:#080d1a;
  --card:#111a2e;
  --card2:#0d1526;
  --text:#e9eefc;
  --muted:#8fa0bd;
  --line:rgba(148,163,184,.16);
  --shadow:0 18px 44px -22px #000;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;background:var(--bg);color:var(--text);font-family:var(--font);
  font-size:15px;line-height:1.7;-webkit-font-smoothing:antialiased;
}
button{font-family:inherit;font-size:inherit;color:inherit;background:none;border:none;cursor:pointer}
input,select{font-family:inherit;font-size:inherit;color:inherit}
h1,h2,h3,h4,p,ul{margin:0}
ul{padding:0;list-style:none}
::selection{background:rgba(99,102,241,.25)}

/* ============ 顶栏 ============ */
.topbar{
  height:64px;display:flex;align-items:center;gap:18px;padding:0 20px;
  border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--bg) 82%,transparent);
  backdrop-filter:blur(14px);position:sticky;top:0;z-index:40;
}
.brand{display:flex;align-items:center;gap:11px;min-width:180px}
.logo{
  width:38px;height:38px;border-radius:12px;display:grid;place-items:center;font-size:20px;
  color:#fff;background:linear-gradient(135deg,#6366f1,#8b5cf6 55%,#06b6d4);
  box-shadow:0 8px 22px -8px rgba(99,102,241,.8);
}
.brand-text{display:flex;flex-direction:column;line-height:1.25}
.brand-text b{font-size:16px;letter-spacing:.3px}
.brand-text small{font-size:11px;color:var(--muted);letter-spacing:1.5px}
.tabs{display:flex;gap:4px;margin:0 auto;background:color-mix(in srgb,var(--muted) 10%,transparent);padding:4px;border-radius:12px}
.tabs button{padding:7px 16px;border-radius:9px;font-size:14px;color:var(--muted);font-weight:500;transition:.18s;position:relative}
.tabs button:hover{color:var(--text)}
.tabs button.active{background:var(--card);color:var(--text);box-shadow:0 2px 10px rgba(15,23,42,.08);font-weight:600}
.top-actions{display:flex;gap:8px}
.icon-btn{
  width:38px;height:38px;border-radius:11px;display:grid;place-items:center;
  border:1px solid var(--line);background:var(--card);font-size:16px;transition:.18s;
}
.icon-btn:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px)}
.only-mobile{display:none}

/* ============ 布局 ============ */
.layout{display:grid;grid-template-columns:290px minmax(0,1fr);height:calc(100vh - 64px)}
.sidebar{
  border-right:1px solid var(--line);display:flex;flex-direction:column;min-height:0;
  background:color-mix(in srgb,var(--card) 45%,var(--bg));
}
.search{position:relative;padding:14px 14px 8px}
.search input{
  width:100%;padding:10px 12px 10px 34px;border-radius:11px;border:1px solid var(--line);
  background:var(--card);outline:none;font-size:13.5px;transition:.2s;
}
.search input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(99,102,241,.12)}
.search-ico{position:absolute;left:26px;top:22px;color:var(--muted);font-size:15px}
.tree{flex:1;overflow-y:auto;padding:6px 10px 18px}
.tree::-webkit-scrollbar,.main::-webkit-scrollbar{width:9px}
.tree::-webkit-scrollbar-thumb,.main::-webkit-scrollbar-thumb{background:color-mix(in srgb,var(--muted) 30%,transparent);border-radius:9px;border:2px solid transparent;background-clip:content-box}
.side-foot{
  padding:10px 16px;border-top:1px solid var(--line);display:flex;justify-content:space-between;
  align-items:center;font-size:11.5px;color:var(--muted);
}
.link-btn{color:var(--muted);font-size:11.5px;text-decoration:underline;text-underline-offset:3px}
.link-btn:hover{color:var(--red)}
.main{overflow-y:auto;padding:26px 30px 70px;scroll-behavior:smooth}
.wrap{max-width:1180px;margin:0 auto}

/* ============ 侧栏树 ============ */
.book-node{margin-bottom:6px}
.book-btn{
  width:100%;display:flex;align-items:center;gap:9px;padding:9px 10px;border-radius:10px;
  font-weight:600;font-size:13.5px;text-align:left;transition:.15s;
}
.book-btn:hover{background:color-mix(in srgb,var(--muted) 10%,transparent)}
.book-btn .bk-dot{width:8px;height:8px;border-radius:50%;background:var(--bc,#6366f1);flex:none}
.book-btn .caret{margin-left:auto;color:var(--muted);font-size:10px;transition:.2s}
.book-node.open .caret{transform:rotate(90deg)}
.book-body{display:none;padding-left:6px}
.book-node.open .book-body{display:block}
.chapter-node{margin:2px 0 2px 8px;border-left:1px solid var(--line);padding-left:6px}
.chapter-btn{
  width:100%;display:flex;align-items:center;gap:7px;padding:6px 8px;border-radius:8px;
  font-size:12.5px;color:var(--muted);text-align:left;
}
.chapter-btn:hover{background:color-mix(in srgb,var(--muted) 10%,transparent);color:var(--text)}
.chapter-body{display:none;padding-left:9px}
.chapter-node.open .chapter-body{display:block}
.chapter-node.open>.chapter-btn{color:var(--text);font-weight:600}
.point-btn{
  width:100%;display:flex;align-items:center;gap:7px;padding:5px 8px;border-radius:7px;
  font-size:12.5px;text-align:left;color:var(--muted);line-height:1.45;
}
.point-btn:hover{background:color-mix(in srgb,var(--muted) 10%,transparent);color:var(--text)}
.point-btn.active{background:color-mix(in srgb,var(--accent) 12%,transparent);color:var(--accent);font-weight:600}
.dot{width:6px;height:6px;border-radius:50%;flex:none;background:color-mix(in srgb,var(--muted) 40%,transparent)}
.dot.weak{background:var(--red)}
.dot.ok{background:var(--amber)}
.dot.strong{background:var(--green)}
.dot.new{background:color-mix(in srgb,var(--muted) 35%,transparent)}
.search-hit{padding:7px 10px;border-radius:9px;font-size:13px;cursor:pointer;display:flex;gap:8px;align-items:center}
.search-hit:hover{background:color-mix(in srgb,var(--muted) 10%,transparent)}
.search-hit small{color:var(--muted);font-size:11px}

/* ============ 通用元素 ============ */
.hero{
  position:relative;overflow:hidden;border-radius:22px;padding:34px 36px;color:#fff;
  background:linear-gradient(120deg,#4f46e5 0%,#7c3aed 45%,#0891b2 100%);
  box-shadow:0 24px 50px -24px rgba(79,70,229,.7);
}
.hero::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(600px 240px at 85% -10%,rgba(255,255,255,.28),transparent 60%),
             radial-gradient(400px 200px at 10% 120%,rgba(6,182,212,.5),transparent 65%);
  pointer-events:none;
}
.hero-inner{position:relative;z-index:1;display:flex;gap:30px;justify-content:space-between;flex-wrap:wrap}
.hero h1{font-size:29px;letter-spacing:.5px;margin-bottom:8px}
.hero p{opacity:.86;max-width:560px;font-size:14px;line-height:1.75}
.hero-actions{display:flex;gap:10px;margin-top:20px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;gap:7px;padding:9px 18px;border-radius:11px;
  font-size:14px;font-weight:600;transition:.18s;border:1px solid transparent;
}
.btn-primary{background:linear-gradient(135deg,#6366f1,#8b5cf6);color:#fff;box-shadow:0 10px 24px -10px rgba(99,102,241,.9)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:0 14px 28px -10px rgba(99,102,241,1)}
.btn-white{background:#fff;color:#4338ca}
.btn-white:hover{transform:translateY(-1px)}
.btn-ghost{border-color:var(--line);color:var(--muted)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.hero .btn-ghost{border-color:rgba(255,255,255,.45);color:#fff}
.hero .btn-ghost:hover{background:rgba(255,255,255,.14);border-color:#fff;color:#fff}
.hero-stats{display:flex;gap:12px;flex-wrap:wrap;align-self:flex-end}
.hstat{
  min-width:96px;padding:12px 16px;border-radius:14px;background:rgba(255,255,255,.16);
  border:1px solid rgba(255,255,255,.24);backdrop-filter:blur(6px);
}
.hstat b{display:block;font-size:23px;line-height:1.2}
.hstat span{font-size:11.5px;opacity:.85;letter-spacing:.5px}

.section-head{display:flex;align-items:center;gap:14px;margin:30px 0 14px}
.section-head h2{font-size:19px;letter-spacing:.3px}
.section-head .rule{flex:1;height:1px;background:var(--line)}
.section-head .sub{font-size:12.5px;color:var(--muted)}

.book-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-top:26px}
.book-tab{
  display:flex;align-items:center;gap:8px;padding:9px 16px;border-radius:12px;
  border:1px solid var(--line);background:var(--card);font-size:13.5px;color:var(--muted);transition:.18s;
}
.book-tab .bk-dot{width:7px;height:7px;border-radius:50%;background:var(--bc)}
.book-tab:hover{color:var(--text);transform:translateY(-1px)}
.book-tab.active{color:#fff;background:var(--bc);border-color:transparent;box-shadow:0 10px 22px -12px var(--bc)}
.book-tab.active .bk-dot{background:#fff}

.book-banner{
  display:flex;align-items:center;gap:18px;padding:20px 24px;border-radius:var(--radius);
  background:linear-gradient(120deg,color-mix(in srgb,var(--bc) 14%,var(--card)),var(--card));
  border:1px solid var(--line);margin-top:20px;
}
.book-banner .bb-icon{
  width:52px;height:52px;border-radius:15px;display:grid;place-items:center;color:#fff;
  font-size:22px;background:var(--bc);box-shadow:0 12px 26px -14px var(--bc);flex:none;
}
.book-banner h2{font-size:19px}
.book-banner p{font-size:12.5px;color:var(--muted);margin-top:2px}
.book-banner .bb-right{margin-left:auto;text-align:right;font-size:12px;color:var(--muted);min-width:130px}
.mini-bar{height:6px;border-radius:6px;background:color-mix(in srgb,var(--muted) 18%,transparent);overflow:hidden;margin-top:7px}
.mini-bar i{display:block;height:100%;border-radius:6px;background:var(--bc);transition:width .5s}

/* 章节流程条 */
.flow{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:18px}
.flow-chip{
  padding:7px 14px;border-radius:999px;white-space:nowrap;font-size:12.5px;
  border:1px dashed color-mix(in srgb,var(--bc) 45%,var(--line));
  background:color-mix(in srgb,var(--bc) 7%,var(--card));color:var(--text);transition:.16s;
}
.flow-chip:hover{border-style:solid;border-color:var(--bc);color:var(--bc);transform:translateY(-1px)}
.flow-arrow{color:var(--muted);font-size:13px;opacity:.55}

.chapter-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(330px,1fr));gap:16px;margin-top:16px}
.chapter-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:18px 18px 14px;box-shadow:var(--shadow);transition:.2s;display:flex;flex-direction:column;
}
.chapter-card:hover{transform:translateY(-2px);border-color:color-mix(in srgb,var(--bc) 45%,var(--line))}
.ch-top{display:flex;align-items:flex-start;gap:10px}
.ch-no{
  font-size:11px;font-weight:700;letter-spacing:.5px;color:var(--bc);
  background:color-mix(in srgb,var(--bc) 12%,transparent);padding:3px 8px;border-radius:7px;flex:none;margin-top:2px;
}
.ch-top h3{font-size:15.5px;line-height:1.45;flex:1}
.ch-mastery{font-size:11px;color:var(--muted);flex:none;text-align:right;line-height:1.4}
.ch-mastery b{display:block;font-size:15px;color:var(--text)}
.ch-sum{font-size:12.5px;color:var(--muted);margin-top:7px;line-height:1.6}
.pills{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px;flex:1;align-content:flex-start}
.pill{
  display:inline-flex;align-items:center;gap:5px;padding:4px 9px;border-radius:8px;
  background:var(--card2);border:1px solid var(--line);font-size:12px;color:var(--text);
  transition:.15s;line-height:1.5;
}
.pill:hover{border-color:var(--bc);color:var(--bc);transform:translateY(-1px)}
.pill .dot{width:5px;height:5px}
.ch-foot{display:flex;align-items:center;justify-content:space-between;margin-top:13px;padding-top:11px;border-top:1px dashed var(--line)}
.ch-foot .meta{font-size:11.5px;color:var(--muted)}
.tiny-btn{font-size:12px;font-weight:600;color:var(--bc);padding:2px 4px}
.tiny-btn:hover{text-decoration:underline;text-underline-offset:3px}

/* ============ 模态详情 ============ */
.modal-root{position:fixed;inset:0;z-index:80;display:none}
.modal-root.show{display:block}
.modal-bg{position:absolute;inset:0;background:rgba(8,13,26,.5);backdrop-filter:blur(4px);animation:fade .2s}
.modal{
  position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);
  width:min(760px,calc(100vw - 32px));max-height:86vh;overflow-y:auto;
  background:var(--card);border-radius:20px;box-shadow:0 40px 80px -30px rgba(0,0,0,.5);
  animation:pop .22s cubic-bezier(.2,.9,.3,1.2);
}
@keyframes fade{from{opacity:0}to{opacity:1}}
@keyframes pop{from{opacity:0;transform:translate(-50%,-46%) scale(.97)}to{opacity:1;transform:translate(-50%,-50%) scale(1)}}
.modal-head{
  display:flex;align-items:center;gap:10px;padding:18px 22px;border-bottom:1px solid var(--line);
  position:sticky;top:0;background:var(--card);z-index:2;border-radius:20px 20px 0 0;
}
.modal-head .crumb{font-size:12px;color:var(--muted)}
.modal-head .dot{width:7px;height:7px}
.modal-close{margin-left:auto;width:32px;height:32px;border-radius:9px;display:grid;place-items:center;color:var(--muted);font-size:18px}
.modal-close:hover{background:var(--card2);color:var(--text)}
.modal-body{padding:20px 24px 24px}
.modal-body h2{font-size:22px;letter-spacing:.3px}
.kp-status{display:flex;gap:8px;align-items:center;margin-top:6px;font-size:12px;color:var(--muted)}
.tag{font-size:11px;padding:2px 8px;border-radius:6px;background:var(--card2);border:1px solid var(--line);color:var(--muted)}
.tag.weak{color:#b91c1c;background:rgba(239,68,68,.1);border-color:rgba(239,68,68,.25)}
.tag.ok{color:#b45309;background:rgba(245,158,11,.12);border-color:rgba(245,158,11,.25)}
.tag.strong{color:#047857;background:rgba(16,185,129,.1);border-color:rgba(16,185,129,.25)}
.detail-block{margin-top:20px}
.detail-block h4{
  font-size:12px;letter-spacing:2px;color:var(--muted);font-weight:600;margin-bottom:9px;
  display:flex;align-items:center;gap:8px;
}
.detail-block h4::after{content:"";height:1px;flex:1;background:var(--line)}
.core-list li{position:relative;padding-left:18px;margin:8px 0;font-size:14px;line-height:1.75}
.core-list li::before{content:"";position:absolute;left:2px;top:10px;width:6px;height:6px;border-radius:50%;background:var(--bc)}
.formula-row{
  display:flex;gap:14px;align-items:baseline;padding:10px 13px;border-radius:10px;background:var(--card2);
  border:1px solid var(--line);margin-bottom:8px;
}
.formula-row code{
  font-family:"Cambria Math","Times New Roman",serif;font-size:16px;color:var(--bc);
  font-weight:600;white-space:nowrap;
}
.formula-row span{font-size:12.5px;color:var(--muted);line-height:1.6}
.trap{
  border-left:3px solid var(--amber);background:rgba(245,158,11,.08);padding:11px 14px;border-radius:0 10px 10px 0;
  font-size:13px;line-height:1.7;margin-bottom:8px;
}
.trap b{color:#b45309;font-size:12px;margin-right:6px}
[data-theme="dark"] .trap b{color:#fbbf24}
.exp-template{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--bg)}
.exp-row{display:flex;gap:14px;padding:11px 14px;border-top:1px solid var(--line)}
.exp-row:first-child{border-top:0}
.exp-k{flex:0 0 84px;font-size:12px;font-weight:700;color:var(--bc);letter-spacing:.02em}
.exp-v{font-size:13px;line-height:1.7;color:var(--text)}
.exp-v ul{margin:0;padding-left:16px}
.exp-v li{margin:2px 0}
.exp-v p{margin:0}
.q-figure{margin:6px 0 16px;padding:10px 12px;border:1px solid var(--line);border-radius:12px;
  background:var(--bg);display:flex;justify-content:center;overflow-x:auto}
.q-figure svg{max-width:100%;height:auto}
.modal-foot{
  display:flex;gap:10px;align-items:center;padding:15px 24px;border-top:1px solid var(--line);
  position:sticky;bottom:0;background:var(--card);border-radius:0 0 20px 20px;
}
.modal-foot .hint{font-size:11.5px;color:var(--muted);margin-right:auto}

/* ============ 练习 / 诊断 ============ */
.setup{max-width:760px;margin:0 auto}
.setup-card{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:26px;box-shadow:var(--shadow)}
.setup-card h2{font-size:21px}
.setup-card>p{color:var(--muted);font-size:13px;margin-top:5px}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:22px}
.field label{display:block;font-size:12px;color:var(--muted);margin-bottom:6px;letter-spacing:.5px}
.field select,.field input[type=number]{
  width:100%;padding:10px 12px;border-radius:10px;border:1px solid var(--line);background:var(--card2);outline:none;
}
.field select:focus{border-color:var(--accent)}
.chip-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}
.chip{padding:6px 13px;border-radius:20px;border:1px solid var(--line);font-size:12.5px;color:var(--muted);transition:.15s}
.chip.on{background:color-mix(in srgb,var(--accent) 14%,transparent);border-color:var(--accent);color:var(--accent);font-weight:600}
.setup-actions{display:flex;gap:10px;margin-top:24px;align-items:center;flex-wrap:wrap}
.setup-note{font-size:12px;color:var(--muted);margin-top:14px;line-height:1.7}
.weak-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:10px;margin-top:14px}
.weak-card{
  padding:12px 14px;border-radius:12px;border:1px solid var(--line);background:var(--card);
  display:flex;align-items:center;gap:10px;transition:.15s;
}
.weak-card:hover{border-color:var(--accent);transform:translateY(-1px)}
.weak-card .wc-main{flex:1;min-width:0}
.weak-card b{display:block;font-size:13px;font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.weak-card small{color:var(--muted);font-size:11px}

.player{max-width:820px;margin:0 auto}
.player-top{display:flex;align-items:center;gap:14px;margin-bottom:18px}
.player-top .back{font-size:12.5px;color:var(--muted);display:flex;align-items:center;gap:5px}
.player-top .back:hover{color:var(--text)}
.track{flex:1;height:7px;border-radius:7px;background:color-mix(in srgb,var(--muted) 16%,transparent);overflow:hidden}
.track i{display:block;height:100%;border-radius:7px;background:linear-gradient(90deg,#6366f1,#8b5cf6);transition:width .3s}
.counter{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums;white-space:nowrap}
.q-card{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:26px 28px;box-shadow:var(--shadow)}
.q-meta{display:flex;align-items:center;gap:8px;font-size:11.5px;color:var(--muted);flex-wrap:wrap}
.q-meta .level{color:var(--amber);letter-spacing:1px}
.q-meta .qtype{color:var(--accent);background:color-mix(in srgb,var(--accent) 12%,transparent);padding:1px 7px;border-radius:5px}
.q-stem{font-size:18px;line-height:1.75;margin:14px 0 20px;font-weight:600;white-space:pre-wrap}
.q-stem .blank{display:inline-block;min-width:58px;border-bottom:2px solid var(--accent);vertical-align:baseline}
.options{display:flex;flex-direction:column;gap:10px}
.opt{
  display:flex;align-items:flex-start;gap:12px;padding:13px 16px;border-radius:12px;
  border:1.5px solid var(--line);background:var(--card2);text-align:left;font-size:14.5px;line-height:1.65;
  transition:.15s;width:100%;
}
.opt:hover:not(.locked){border-color:var(--accent);background:color-mix(in srgb,var(--accent) 6%,var(--card2))}
.opt .letter{
  width:24px;height:24px;border-radius:7px;display:grid;place-items:center;flex:none;
  background:var(--card);border:1px solid var(--line);font-size:12px;font-weight:700;color:var(--muted);margin-top:1px;
}
.opt.sel{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 10%,var(--card2))}
.opt.sel .letter{background:var(--accent);border-color:var(--accent);color:#fff}
.opt.correct{border-color:var(--green);background:rgba(16,185,129,.1)}
.opt.correct .letter{background:var(--green);border-color:var(--green);color:#fff}
.opt.wrong{border-color:var(--red);background:rgba(239,68,68,.1)}
.opt.wrong .letter{background:var(--red);border-color:var(--red);color:#fff}
.opt.locked{cursor:default}
.opt .opt-note{font-size:11.5px;color:var(--muted);margin-left:auto;flex:none}
.explain{
  margin-top:18px;border-radius:13px;padding:15px 17px;font-size:13.5px;line-height:1.8;
  background:var(--card2);border:1px solid var(--line);animation:fade .25s;
}
.explain .ex-head{display:flex;align-items:center;gap:8px;font-weight:700;margin-bottom:6px;font-size:13px}
.explain.right .ex-head{color:var(--green)}
.explain.bad .ex-head{color:var(--red)}
.q-foot{display:flex;align-items:center;gap:12px;margin-top:20px}
.q-foot .hint{font-size:11.5px;color:var(--muted);margin-right:auto}
.kbd{display:inline-block;padding:1px 5px;border:1px solid var(--line);border-bottom-width:2px;border-radius:4px;font-size:10px;color:var(--muted)}

/* ============ 结果 ============ */
.result{max-width:760px;margin:0 auto;text-align:center;background:var(--card);border:1px solid var(--line);border-radius:22px;padding:36px 30px;box-shadow:var(--shadow)}
.ring{
  width:132px;height:132px;border-radius:50%;margin:0 auto 18px;display:grid;place-items:center;position:relative;
  background:conic-gradient(var(--ring-c,#6366f1) calc(var(--pct)*1%), color-mix(in srgb,var(--muted) 16%,transparent) 0);
}
.ring::before{content:"";position:absolute;inset:9px;border-radius:50%;background:var(--card)}
.ring b{position:relative;font-size:31px;line-height:1}
.ring b small{font-size:13px;color:var(--muted)}
.result h2{font-size:22px}
.result>p{color:var(--muted);font-size:13.5px;margin-top:5px}
.result-stats{display:flex;justify-content:center;gap:26px;margin:22px 0;flex-wrap:wrap}
.result-stats div{font-size:12px;color:var(--muted)}
.result-stats b{display:block;font-size:21px;color:var(--text)}
.result .weak-list{text-align:left;margin-top:8px}
.result .actions{display:flex;gap:10px;justify-content:center;margin-top:26px;flex-wrap:wrap}

/* ============ 报告 ============ */
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:14px}
.stat{
  background:var(--card);border:1px solid var(--line);border-radius:15px;padding:17px 18px;box-shadow:var(--shadow);
}
.stat span{font-size:12px;color:var(--muted)}
.stat b{display:block;font-size:27px;line-height:1.3;letter-spacing:.5px}
.stat b small{font-size:13px;color:var(--muted);font-weight:400;margin-left:2px}
.stat .sub{font-size:11px;color:var(--muted)}
.report-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:18px;margin-top:18px;align-items:start}
.report-grid[data-single]{grid-template-columns:1fr}
.panel{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px;box-shadow:var(--shadow)}
.panel h3{font-size:14.5px;margin-bottom:4px}
.panel .ph{font-size:11.5px;color:var(--muted);margin-bottom:15px}
.book-row{margin-bottom:15px}
.book-row .br-top{display:flex;align-items:center;gap:8px;font-size:12.5px;margin-bottom:5px}
.book-row .br-top b{font-weight:600}
.book-row .br-top span{margin-left:auto;color:var(--muted);font-size:11.5px}
.bar{height:7px;border-radius:7px;background:color-mix(in srgb,var(--muted) 14%,transparent);overflow:hidden;display:flex}
.bar i{display:block;height:100%;transition:width .5s}
.bar .b-strong{background:var(--green)}
.bar .b-ok{background:var(--amber)}
.bar .b-weak{background:var(--red)}
.legend{display:flex;gap:14px;font-size:11px;color:var(--muted);margin-top:12px;flex-wrap:wrap}
.legend i{display:inline-block;width:8px;height:8px;border-radius:2px;margin-right:4px}
.wrong-item{padding:10px 0;border-bottom:1px dashed var(--line);display:flex;gap:10px;align-items:flex-start}
.wrong-item:last-child{border-bottom:none}
.wrong-item .wi-main{flex:1;min-width:0}
.wrong-item b{display:block;font-size:12.5px;font-weight:500;line-height:1.55;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.wrong-item small{color:var(--muted);font-size:11px}
.empty{padding:26px;text-align:center;color:var(--muted);font-size:12.5px;line-height:1.9}
.empty .big{font-size:28px;display:block;margin-bottom:6px;opacity:.6}

/* ============ 提示 & 引导 ============ */
.toast{
  position:fixed;left:50%;bottom:26px;transform:translate(-50%,20px);opacity:0;pointer-events:none;
  background:#0f172a;color:#fff;font-size:13px;padding:10px 18px;border-radius:11px;z-index:120;
  transition:.25s;box-shadow:0 16px 36px -12px rgba(0,0,0,.6);max-width:80vw;
}
[data-theme="dark"] .toast{background:#e9eefc;color:#0f172a}
.toast.show{opacity:1;transform:translate(-50%,0)}
.guide-step{display:flex;gap:14px;padding:12px 0;border-bottom:1px dashed var(--line)}
.guide-step:last-child{border:none}
.guide-step .gi{
  width:30px;height:30px;border-radius:9px;flex:none;display:grid;place-items:center;
  background:color-mix(in srgb,var(--accent) 13%,transparent);color:var(--accent);font-weight:700;font-size:13px;
}
.guide-step b{font-size:13.5px;display:block}
.guide-step p{font-size:12.5px;color:var(--muted);line-height:1.7;margin-top:2px}

/* ============ 响应式 ============ */
@media (max-width:1060px){
  .report-grid{grid-template-columns:1fr}
}
/* ============ 公式 / 详解 / AI ============ */
.tex{font-size:1.02em}
.tex .katex{font-size:1.06em}
.formula-row .tex{flex:0 0 auto;padding:3px 10px;border-radius:8px;background:color-mix(in srgb,var(--accent) 8%,transparent);border:1px solid color-mix(in srgb,var(--accent) 16%,transparent)}
.eg-box{padding:12px 14px;border-left:3px solid var(--accent);border-radius:0 10px 10px 0;background:color-mix(in srgb,var(--accent) 5%,var(--bg));font-size:13.5px;line-height:1.85}
.eg-detail{margin-top:4px;border:1px solid var(--line);border-radius:12px;overflow:hidden}
.eg-detail summary{cursor:pointer;list-style:none;padding:12px 14px;font-weight:600;font-size:13.5px;line-height:1.7;background:color-mix(in srgb,var(--text) 3%,transparent)}
.eg-detail summary::-webkit-details-marker{display:none}
.eg-detail summary .eg-toggle{float:right;margin-left:12px;font-weight:500;font-size:12px;color:var(--accent)}
.eg-detail[open] .eg-toggle{display:none}
.eg-body{padding:6px 14px 14px;font-size:13px;line-height:1.8;border-top:1px dashed var(--line)}
.eg-opt{display:flex;gap:8px;padding:4px 8px;border-radius:8px;margin-top:3px;color:var(--muted)}
.eg-opt b{color:var(--text)}
.eg-opt.right{background:color-mix(in srgb,var(--green) 10%,transparent);color:var(--text)}
.eg-opt.right b{color:var(--green)}
.eg-ans{margin:8px 0;font-weight:700;color:var(--green);font-size:13px}
.eg-body p{margin:6px 0 0;color:var(--muted)}

.ai-fab{position:fixed;right:22px;bottom:22px;z-index:64;display:flex;align-items:center;gap:7px;
  padding:11px 18px;border-radius:999px;border:none;cursor:pointer;color:#fff;font-size:13.5px;font-weight:600;
  background:linear-gradient(135deg,#6366f1,#8b5cf6);box-shadow:0 10px 30px -10px rgba(99,102,241,.8)}
.ai-fab span{font-size:15px}
.ai-fab:hover{transform:translateY(-1px)}
.ai-panel{position:fixed;top:0;right:0;bottom:0;width:min(410px,100vw);z-index:95;display:flex;flex-direction:column;
  background:var(--card);border-left:1px solid var(--line);box-shadow:-20px 0 60px -30px rgba(0,0,0,.5);
  transform:translateX(104%);transition:transform .25s ease}
.ai-panel.show{transform:none}
.ai-head{display:flex;align-items:center;gap:6px;padding:12px 14px;border-bottom:1px solid var(--line)}
.ai-title{flex:1;display:flex;flex-direction:column;line-height:1.3}
.ai-title small{font-size:10.5px;color:var(--muted);font-weight:400}
.ai-msgs{flex:1;overflow-y:auto;padding:14px;background:var(--bg)}
.ai-msg{display:flex;gap:8px;margin-bottom:12px;align-items:flex-start}
.ai-msg.user{justify-content:flex-end}
.ai-avatar{flex:0 0 24px;height:24px;border-radius:50%;display:grid;place-items:center;color:#fff;font-size:12px;
  background:linear-gradient(135deg,#6366f1,#8b5cf6);margin-top:2px}
.ai-bubble{max-width:84%;padding:9px 12px;border-radius:12px;background:var(--card);border:1px solid var(--line);
  font-size:13px;line-height:1.75;word-break:break-word}
.ai-msg.user .ai-bubble{background:var(--accent);border-color:transparent;color:#fff}
.ai-msg.err .ai-bubble{background:#fff5f5;border-color:#f3c2c2;color:#a33}
[data-theme="dark"] .ai-msg.err .ai-bubble{background:#2a1618;border-color:#5b2a2a;color:#f3a3a3}
.ai-bubble code{font-size:12px;padding:1px 5px;border-radius:4px;background:color-mix(in srgb,var(--text) 8%,transparent)}
.ai-welcome{text-align:center;padding:28px 18px;color:var(--muted)}
.ai-welcome b{display:block;color:var(--text);font-size:15px;margin:10px 0 4px}
.ai-welcome p{font-size:12.5px;line-height:1.8;max-width:280px;margin:0 auto}
.ai-orb{width:44px;height:44px;margin:0 auto;border-radius:14px;display:grid;place-items:center;color:#fff;font-size:20px;
  background:linear-gradient(135deg,#6366f1,#8b5cf6)}
.ai-quick{display:flex;flex-wrap:wrap;gap:6px;padding:8px 12px;border-top:1px solid var(--line);background:var(--card)}
.ai-quick button{font-size:11.5px;padding:5px 10px;border-radius:999px;border:1px solid var(--line);background:transparent;color:var(--muted);cursor:pointer}
.ai-quick button:hover{color:var(--accent);border-color:var(--accent)}
.ai-form{display:flex;gap:8px;padding:10px 12px;border-top:1px solid var(--line);background:var(--card)}
.ai-form textarea{flex:1;resize:none;border:1px solid var(--line);border-radius:10px;padding:8px 10px;font:inherit;font-size:13px;
  background:var(--bg);color:var(--text);line-height:1.5;outline:none}
.ai-form textarea:focus{border-color:var(--accent)}
.ai-form .btn{height:auto;align-self:stretch;padding:0 16px}
.ai-foot{display:flex;justify-content:space-between;align-items:center;padding:0 14px 10px;font-size:10.5px;color:var(--muted);background:var(--card)}

/* 计时与错因 */
.timer{font-variant-numeric:tabular-nums;color:var(--red);font-weight:700;letter-spacing:.5px}
.timer.low{animation:blink 1.1s steps(2,start) infinite}
@keyframes blink{50%{opacity:.35}}
.why-row{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin-top:12px;padding-top:10px;border-top:1px dashed color-mix(in srgb,var(--line) 80%,transparent)}
.why-label{font-size:12px;color:var(--muted);margin-right:2px}
.why-chip{font:inherit;font-size:12px;padding:4px 10px;border-radius:999px;border:1px solid var(--line);
  background:var(--card);color:var(--text);cursor:pointer;transition:.15s}
.why-chip:hover{border-color:var(--accent);color:var(--accent)}
.why-chip.on{background:color-mix(in srgb,var(--red) 12%,transparent);border-color:var(--red);color:var(--red)}
.why-tip{font-size:11px;color:var(--muted);margin-left:2px}
.why-advice{font-size:11px;color:var(--muted);margin-top:3px}
.why-advice + .bar{margin-top:2px}

/* 今日复习 */
.review-strip{display:flex;align-items:center;justify-content:space-between;gap:18px;margin:16px 0 14px;
  padding:16px 20px;border-radius:var(--radius);border:1px solid color-mix(in srgb,var(--accent) 26%,var(--line));
  background:linear-gradient(120deg,color-mix(in srgb,var(--accent) 11%,var(--card)),var(--card))}
.review-strip b{font-size:16px}
.review-strip small{display:block;font-size:12px;color:var(--muted);margin-top:4px;line-height:1.55}
.tab-badge{position:absolute;top:1px;right:6px;min-width:16px;height:16px;padding:0 4px;border-radius:9px;
  background:var(--red);color:#fff;font-size:10px;font-style:normal;line-height:16px;text-align:center}

@media (max-width:900px){
  .topbar{padding:0 12px;gap:10px;backdrop-filter:none;background:var(--bg)}
  .only-mobile{display:grid}
  .brand{min-width:0}
  .brand-text small{display:none}
  .tabs{position:fixed;left:0;right:0;bottom:0;margin:0;border-radius:0;padding:6px 8px calc(6px + env(safe-area-inset-bottom));
    background:color-mix(in srgb,var(--card) 94%,transparent);backdrop-filter:blur(16px);
    border-top:1px solid var(--line);z-index:60;justify-content:space-around}
  .tabs button{flex:1;font-size:12px;padding:6px 4px;text-align:center}
  .layout{grid-template-columns:1fr;height:calc(100vh - 64px)}
  .sidebar{position:fixed;left:0;top:64px;bottom:56px;width:270px;z-index:70;transform:translateX(-102%);
    transition:.25s;box-shadow:20px 0 60px -30px #000;background:var(--bg)}
  .sidebar.open{transform:none}
  .main{padding:18px 15px 90px}
  .hero{padding:26px 22px}
  .hero h1{font-size:23px}
  .hero-stats{width:100%}
  .hstat{flex:1;min-width:0;padding:10px 8px}
  .hstat span{font-size:10.5px;letter-spacing:0;white-space:nowrap}
  .hstat b{font-size:19px}
  .chapter-grid{grid-template-columns:1fr}
  .form-grid{grid-template-columns:1fr}
  .q-card{padding:20px 18px}
  .q-stem{font-size:16.5px}
  .modal{width:calc(100vw - 18px);max-height:90vh}
  .modal-foot{gap:8px;padding:12px 16px}
  .modal-foot .hint{display:none}
  .modal-foot .btn{flex:1;min-width:0;white-space:nowrap;padding:10px 6px;font-size:13px}
  .q-foot .hint{display:none}
  .ai-fab{right:14px;bottom:74px;padding:10px 15px;font-size:12.5px}
  .ai-panel{width:100%}
  .report-head{flex-wrap:wrap;gap:8px;align-items:center}
  .report-head h2{width:100%}
  .report-head .rule{display:none}
  .report-head .sub{width:100%;order:6}
  .report-head .btn{flex:1 1 40%;justify-content:center}
  .modal-body{max-height:calc(90vh - 130px)}
}

/* ============ 模拟高考 ============ */
.exam-intro{background:var(--card);border:1px solid var(--line);border-left:3px solid var(--accent);border-radius:12px;padding:16px 18px;margin-bottom:18px;color:var(--muted);font-size:13px;line-height:1.75}
.exam-intro p{margin:0 0 6px}
.exam-intro p:last-child{margin:0}
.paper-list{display:grid;gap:16px}
.paper-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px 24px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.paper-card::before{content:'';position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--pc)}
.paper-top{display:flex;align-items:center;justify-content:space-between;gap:10px}
.paper-time{font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}
.paper-card h2{font-size:19px;margin:10px 0 8px}
.paper-desc{margin:0 0 10px;color:var(--muted);font-size:13px;line-height:1.7}
.paper-meta{font-size:12px;color:var(--muted)}
.paper-foot{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:16px;padding-top:14px;border-top:1px dashed var(--line)}
.paper-last{font-size:12px;color:var(--muted)}
.paper-player{max-width:860px}
.paper-player .counter{margin-left:auto}
.paper-player .player-top{gap:12px}
.player-progress{height:4px;border-radius:99px;background:var(--line);overflow:hidden;margin:-4px 0 18px}
.player-progress i{display:block;height:100%;background:var(--accent);border-radius:99px;transition:width .25s}
.paper-player .player-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:16px}
.paper-player .player-note{margin-top:10px;text-align:center;font-size:12px;color:var(--muted)}
.q-score{font-size:11.5px;color:var(--accent);background:color-mix(in srgb,var(--accent) 12%,transparent);padding:1px 7px;border-radius:5px}
.paper-text{width:100%;min-height:150px;margin-top:14px;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--text);font:inherit;font-size:13.5px;line-height:1.7;resize:vertical}
.paper-text:focus{outline:none;border-color:var(--accent)}
.paper-section{margin-top:16px;padding:20px 22px;background:var(--card);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow)}
.paper-result{max-width:920px;margin:0 auto}
.paper-result .result{padding:26px 20px 18px;max-width:none}
.paper-result .paper-section{margin-top:14px}
.free-grade{border-top:1px dashed var(--line);padding:14px 0 6px}
.free-grade:first-of-type{border-top:0;padding-top:4px}
.fg-stem{font-size:13.5px;line-height:1.75;margin-bottom:8px;white-space:pre-wrap}
.fg-answer summary{cursor:pointer;color:var(--accent);font-size:12.5px;list-style:none}
.fg-answer summary::-webkit-details-marker{display:none}
.fg-answer summary::before{content:'▸ ';font-size:11px}
.fg-answer[open] summary::before{content:'▾ '}
.answer-box{margin-top:8px;padding:12px 14px;border-radius:10px;background:var(--bg);border:1px solid var(--line);font-size:13px;line-height:1.8;white-space:pre-wrap}
.point-list{margin:8px 0 0;padding-left:20px;font-size:12.5px;color:var(--muted);line-height:1.8}
.rate-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:10px}
.rate-row .hint{font-size:12px}
.rate-chip{font-size:12px;padding:4px 12px}
.sec-table{display:grid;gap:10px}
.sec-row{display:grid;grid-template-columns:minmax(90px,1.1fr) 2fr auto;align-items:center;gap:12px;font-size:12.5px}
.sec-row b{font-variant-numeric:tabular-nums;white-space:nowrap}
.sec-bar{height:7px;border-radius:99px;background:var(--line);overflow:hidden}
.sec-bar i{display:block;height:100%;background:var(--accent);border-radius:99px}
@media (max-width:700px){
  .paper-card{padding:18px 16px}
  .paper-foot{flex-direction:column;align-items:stretch}
  .paper-foot .btn{width:100%}
  .paper-player .player-top{flex-wrap:wrap;gap:8px}
  .paper-player .counter{margin-left:0}
  .sec-row{grid-template-columns:1fr auto;gap:6px 10px}
  .sec-row .sec-bar{grid-column:1 / -1;grid-row:2}
}

/* ============ 公式默写 ============ */
.formula-top{display:flex;align-items:center;gap:16px;background:var(--card);border:1px solid var(--line);
  border-radius:16px;padding:14px 18px;margin:12px 0 8px;box-shadow:var(--shadow)}
.ft-main b{font-size:24px;letter-spacing:-.02em}
.ft-main small{font-size:13px;color:var(--muted);font-weight:500}
.ft-main span{display:block;font-size:11.5px;color:var(--muted);margin-top:2px}
.ft-bar{flex:1;height:8px;border-radius:99px;background:color-mix(in srgb,var(--muted) 18%,transparent);overflow:hidden}
.ft-bar i{display:block;height:100%;background:var(--green);border-radius:99px;transition:width .3s}
.mode-chips{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0 16px}
.mode-chips .chip em{font-style:normal;opacity:.7;margin-left:2px}
.fcard{background:var(--card);border:1px solid var(--line);border-radius:22px;box-shadow:var(--shadow);
  padding:24px 26px;min-height:320px;display:flex;flex-direction:column}
.fc-meta{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);flex-wrap:wrap}
.fc-meta .pill{--pc:var(--accent)}
.fc-index{margin-left:auto}
.fc-body{flex:1;display:flex;align-items:center;justify-content:center;text-align:center;padding:16px 0}
.fc-prompt{width:100%}
.fc-label{display:inline-block;font-size:11.5px;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);margin-bottom:10px}
.fc-q{font-size:22px;font-weight:650;line-height:1.65;max-width:560px;margin:0 auto}
.fc-hint{font-size:12.5px;color:var(--muted);margin-top:12px}
.fc-formula{font-size:26px;line-height:1.7;padding:18px 16px;margin:6px 0 14px;border-radius:14px;
  border:1px dashed color-mix(in srgb,var(--accent) 40%,var(--line));background:color-mix(in srgb,var(--accent) 6%,transparent)}
.fc-cond{font-size:13px;color:var(--text);background:color-mix(in srgb,var(--amber) 12%,transparent);
  border-left:3px solid var(--amber);border-radius:8px;padding:10px 12px;text-align:left;line-height:1.65}
.fc-cond b{display:block;font-size:11px;color:var(--amber);margin-bottom:2px;letter-spacing:.06em}
.fc-note{font-size:12.5px;color:var(--muted);margin-top:10px;text-align:left}
.fc-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:18px}
.fc-status{text-align:center;font-size:12px;color:var(--muted);margin-top:12px}
.empty-card{min-height:300px;align-items:center;justify-content:center;text-align:center}
.fc-empty{display:flex;flex-direction:column;align-items:center;gap:6px;padding:18px}
.fc-empty .big{font-size:30px;color:var(--green)}
.fc-empty b{font-size:17px}
.fc-empty .actions{margin-top:12px}

/* 分步解析 */
.step-box{background:color-mix(in srgb,var(--accent) 6%,transparent);border:1px dashed var(--line);
  border-radius:12px;padding:12px 14px;margin:10px 0 4px}
.step-head{display:flex;align-items:baseline;gap:10px;flex-wrap:wrap}
.step-head b{font-size:13px}
.step-list{margin:10px 0 0 18px;font-size:13.5px;line-height:1.75}
.step-list li{margin:4px 0}
.step-actions{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:12px}
.ex-full{font-size:14px;line-height:1.78}
.explain .why-row{margin-top:12px}

/* ============ 答题卡 ============ */
.sheet-grid{display:flex;flex-wrap:wrap;gap:6px;margin:12px 0 14px}
.sheet-cell{width:30px;height:30px;border-radius:8px;border:1px solid var(--line);background:var(--card);
  font-size:12px;font-weight:600;color:var(--muted);transition:.15s;position:relative}
.sheet-cell:hover{border-color:var(--accent);color:var(--accent)}
.sheet-cell.done{background:color-mix(in srgb,var(--accent) 14%,transparent);color:var(--accent);
  border-color:color-mix(in srgb,var(--accent) 40%,var(--line))}
.sheet-cell.cur{outline:2px solid var(--accent);outline-offset:1px;color:var(--text)}
.sheet-cell.mark::after{content:'';position:absolute;top:-2px;right:-2px;width:8px;height:8px;
  border-radius:50%;background:var(--amber);box-shadow:0 0 0 2px var(--card)}
.tiny-btn.on{color:var(--amber)}
.ans-wrap{overflow-x:auto;margin-top:8px}
.ans-table{width:100%;border-collapse:collapse;font-size:13px;min-width:420px}
.ans-table th{text-align:left;font-size:11.5px;color:var(--muted);font-weight:600;padding:6px 10px;
  border-bottom:1px solid var(--line);letter-spacing:.04em}
.ans-table td{padding:7px 10px;border-bottom:1px dashed color-mix(in srgb,var(--line) 70%,transparent)}
.ans-table tr:last-child td{border-bottom:none}
.ans-table .st-ok td:last-child{color:var(--green);font-weight:700}
.ans-table .st-bad td:last-child{color:var(--red);font-weight:700}
.ans-table .st-part td:last-child{color:var(--amber);font-weight:700}
.ans-table .st-miss td{color:var(--muted)}
.flag{color:var(--amber);font-size:11px}

/* 周报 */
.week-panel{margin:14px 0}
.week-bars{display:flex;align-items:flex-end;gap:14px;height:120px;padding:4px 6px 0}
.wb{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:flex-end;height:100%;gap:3px}
.wb i{width:60%;max-width:34px;min-height:2px;border-radius:6px 6px 2px 2px;
  background:color-mix(in srgb,var(--accent) 45%,transparent);transition:height .3s}
.wb.today i{background:var(--accent)}
.wb b{font-size:10.5px;color:var(--muted);height:13px}
.wb span{font-size:10.5px;color:var(--muted)}
.wb.today span{color:var(--accent);font-weight:700}
.week-empty{display:flex;align-items:center;justify-content:center;width:100%;height:80px;
  font-size:12.5px;color:var(--muted);text-align:center;line-height:1.7}
.rs-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}

@media (max-width:640px){
  .formula-top{flex-wrap:wrap;gap:10px}
  .ft-bar{order:3;flex-basis:100%}
  .fcard{padding:18px 16px;min-height:280px}
  .fc-q{font-size:19px}
  .fc-formula{font-size:21px}
  .fc-foot{flex-wrap:wrap}
  .fc-foot .btn{flex:1;justify-content:center}
  .week-bars{gap:8px;height:100px}
}

/* ============ 打印 ============ */
@media print{
  .topbar,.sidebar,.toast,.modal-root,.ai-fab,.ai-panel{display:none!important}
  .layout{display:block;height:auto}
  .main{overflow:visible;padding:0}
  .hero{box-shadow:none}
  .chapter-card{break-inside:avoid;box-shadow:none}
  .book-tabs{display:none}
  body{background:#fff}
}

/* ==================== 待办升级：真题 / 二刷 / 答题卡 / 计划 / 趋势 / 打印 ==================== */
.paper-filters{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin:10px 0 14px}
.paper-filters .chip-row{margin:0}
.filter-sep{width:1px;height:20px;background:var(--line);display:inline-block;margin:0 2px}
.pill-real{background:color-mix(in srgb,var(--green) 14%,transparent);color:var(--green);border-color:color-mix(in srgb,var(--green) 30%,transparent)}
.ex-compare{font-size:12.5px;line-height:1.7;padding:8px 10px;border-radius:10px;margin-bottom:10px;background:var(--card2);border:1px solid var(--line)}
.ex-compare.good{border-color:color-mix(in srgb,var(--green) 30%,transparent);background:color-mix(in srgb,var(--green) 8%,transparent)}
.ex-compare.again{border-color:color-mix(in srgb,var(--amber) 35%,transparent);background:color-mix(in srgb,var(--amber) 9%,transparent)}
.q-meta .tiny-btn{margin-left:auto}
.practice-sheet{margin:0 0 12px}
.plan-panel{padding:14px 16px;margin:14px 0}
.plan-head{display:flex;align-items:baseline;gap:10px;flex-wrap:wrap;margin-bottom:10px}
.plan-head b{font-size:14px}
.plan-row{display:flex;align-items:flex-end;gap:12px;flex-wrap:wrap}
.plan-field{display:flex;flex-direction:column;gap:4px;font-size:11.5px;color:var(--muted)}
.plan-field input{padding:7px 9px;border-radius:9px;border:1px solid var(--line);background:var(--card);color:var(--text);font:inherit;font-size:13px}
.plan-stat{font-size:12px;color:var(--muted);margin-left:auto}
.plan-stat b{color:var(--text);font-size:14px}
.trend-panel{padding:14px 16px;margin-bottom:14px}
.trend-svg{width:100%;height:110px;display:block;margin-top:4px;overflow:visible}
.trend-axis{stroke:var(--line);stroke-width:1}
.trend-grid{stroke:var(--line);stroke-dasharray:3 4;stroke-width:1}
.trend-line{fill:none;stroke:var(--accent);stroke-width:2;stroke-linejoin:round;stroke-linecap:round;vector-effect:non-scaling-stroke}
.trend-dot{fill:var(--accent)}
.trend-dot:hover{fill:var(--green)}
.trend-labels{display:flex;justify-content:space-between;font-size:11px;color:var(--muted);margin-top:2px}
.print-list{display:flex;flex-direction:column;gap:8px}
.print-item{display:flex;flex-direction:column;gap:3px;text-align:left;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--card);cursor:pointer;font:inherit;color:var(--text)}
.print-item:hover{border-color:var(--accent);background:var(--card2)}
.print-item b{font-size:13.5px}
.print-item small{font-size:11.5px;color:var(--muted)}
body.ai-hide .ai-fab{display:none}
.search-sub{font-size:10.5px;color:var(--muted);padding:8px 10px 4px;letter-spacing:.04em}
.search-hit.q-hit div div{font-size:12px;line-height:1.5}
@media (max-width:900px){
  .plan-stat{margin-left:0;width:100%}
  .trend-svg{height:96px}
}

/* ==================== 学习页 / 概念词典 ==================== */
.dict-btn{display:flex;align-items:center;gap:6px;width:calc(100% - 24px);margin:8px 12px 2px;
  padding:7px 10px;border:1px dashed var(--line);border-radius:10px;background:transparent;
  color:var(--muted);font:inherit;font-size:11.5px;cursor:pointer;justify-content:center}
.dict-btn:hover{color:var(--accent);border-color:var(--accent);background:var(--card2)}
.learn-wrap{max-width:1120px;margin:0 auto}
.learn-top{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px 26px;box-shadow:var(--shadow);margin-bottom:18px}
.learn-crumb{font-size:11.5px;color:var(--muted);letter-spacing:.04em}
.learn-title{display:flex;align-items:center;gap:12px;margin:8px 0 10px;flex-wrap:wrap}
.learn-title h1{font-size:26px;letter-spacing:-.02em}
.learn-def{font-size:15.5px;line-height:1.85;color:var(--text);max-width:74ch}
.learn-meta{display:flex;gap:16px;flex-wrap:wrap;font-size:11.5px;color:var(--muted);margin-top:12px}
.learn-acts{margin-top:16px;gap:8px}
.learn-cols{display:grid;grid-template-columns:180px minmax(0,1fr);gap:20px;align-items:start}
.learn-nav{position:sticky;top:16px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px}
.ln-title{font-size:10.5px;color:var(--muted);letter-spacing:.08em;margin:2px 6px 8px}
.learn-nav a{display:block;padding:7px 8px;border-radius:8px;color:var(--muted);font-size:12.5px;text-decoration:none}
.learn-nav a:hover{background:var(--card2);color:var(--text)}
.learn-main{display:flex;flex-direction:column;gap:14px}
.learn-sec{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px 22px;scroll-margin-top:20px}
.learn-sec h2{font-size:15px;margin-bottom:12px;letter-spacing:-.01em}
.learn-sec h2::before{content:"";display:inline-block;width:4px;height:13px;border-radius:2px;background:var(--accent);margin-right:9px;vertical-align:-1px}
.learn-ul{margin:0;padding-left:18px;display:flex;flex-direction:column;gap:8px;font-size:13.5px;line-height:1.8}
.learn-ul.traps li::marker{color:var(--amber)}
.term-list{margin:0;display:flex;flex-direction:column;gap:12px}
.term dt{font-weight:700;font-size:13.5px;margin-bottom:2px}
.term dd{margin:0;font-size:13px;line-height:1.75;color:var(--muted)}
.cmp-list{display:flex;flex-direction:column;gap:12px}
.cmp-row{border-left:2px solid var(--line);padding-left:12px}
.cmp-pair{display:flex;align-items:center;gap:8px;font-size:13px}
.cmp-pair i{font-style:normal;color:var(--muted);font-size:11px}
.cmp-row p{margin:4px 0 0;font-size:13px;line-height:1.75;color:var(--muted)}
.learn-note{margin:10px 0 0;font-size:11.5px;color:var(--muted)}
.learn-exam{margin:0;font-size:13.5px;line-height:1.85}
.learn-example .le-stem{font-size:14px;line-height:1.7;font-weight:600}
.le-opts{list-style:none;margin:10px 0;padding:0;display:flex;flex-direction:column;gap:6px}
.le-opts li{display:flex;gap:9px;font-size:13px;line-height:1.65;padding:7px 10px;border:1px solid var(--line);border-radius:9px;background:var(--card2)}
.le-opts b{color:var(--muted);min-width:14px}
.le-detail{border-top:1px dashed var(--line);padding-top:10px;margin-top:6px}
.le-detail summary{cursor:pointer;font-size:12.5px;color:var(--accent)}
.le-answer{font-size:12.5px;color:var(--green);margin:8px 0 4px;font-weight:600}
.le-detail p{margin:4px 0 0;font-size:13px;line-height:1.8;color:var(--muted)}
.quiz-cta{display:flex;gap:10px;flex-wrap:wrap;margin-top:12px}
.learn-source{font-size:11px;color:var(--muted);margin:2px 2px 0}
.dict-wrap{max-width:820px}
.dict-search{display:flex;align-items:center;gap:8px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:10px 12px;margin:8px 0 14px}
.dict-search input{flex:1;border:0;background:transparent;color:var(--text);font:inherit;font-size:14px;outline:none}
.dict-list{display:flex;flex-direction:column;gap:6px}
.dict-item{display:flex;align-items:center;gap:10px;width:100%;text-align:left;padding:10px 12px;border:1px solid var(--line);border-radius:11px;background:var(--card);color:var(--text);font:inherit;cursor:pointer}
.dict-item:hover{border-color:var(--accent);background:var(--card2)}
.dict-kind{font-size:10px;color:var(--muted);border:1px solid var(--line);border-radius:6px;padding:2px 6px;flex:none}
.dict-main{flex:1;min-width:0;display:flex;flex-direction:column;gap:1px}
.dict-main b{font-size:13.5px;font-weight:600}
.dict-main small{font-size:11.5px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.dict-arrow{color:var(--muted)}
@media (max-width:900px){
  .learn-top{padding:18px 16px}
  .learn-title h1{font-size:22px}
  .learn-def{font-size:14px}
  .learn-cols{grid-template-columns:1fr}
  .learn-nav{position:static;display:flex;gap:4px;overflow-x:auto;padding:8px}
  .ln-title{display:none}
  .learn-nav a{white-space:nowrap;background:var(--card2);padding:6px 10px}
  .learn-sec{padding:16px 15px}
  .learn-acts .btn{flex:1 1 42%}
}
@media print{
  .learn-nav,.learn-acts,.dict-btn{display:none!important}
  .learn-cols{grid-template-columns:1fr}
  .learn-sec{break-inside:avoid}
}

/* 符号索引 · 公式掌握状态 · 试卷校对 */
.dict-sym{font-size:10px;color:var(--accent);border:1px solid color-mix(in srgb,var(--accent) 28%,transparent);
  background:color-mix(in srgb,var(--accent) 8%,transparent);border-radius:6px;padding:2px 6px;flex:none;
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace;letter-spacing:.02em}
.search-hit .dict-sym{margin-left:6px}
.formula-row .f-state{margin-left:auto;align-self:center;font-size:11px;white-space:nowrap;
  padding:2px 8px;border-radius:999px;border:1px solid var(--line);color:var(--muted);flex:none}
.f-state.done{color:var(--green);border-color:color-mix(in srgb,var(--green) 35%,transparent);
  background:color-mix(in srgb,var(--green) 10%,transparent)}
.f-state.review{color:var(--accent);border-color:color-mix(in srgb,var(--accent) 35%,transparent);
  background:color-mix(in srgb,var(--accent) 8%,transparent)}
.f-state.due{color:var(--amber)}
.learn-cta{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:space-between;
  margin-top:12px;padding:10px 12px;border:1px dashed var(--line);border-radius:10px;background:var(--card2)}
.point-scope .chip{cursor:default}
.pill-audit{background:color-mix(in srgb,var(--muted) 10%,transparent);color:var(--muted);border:1px solid var(--line);font-size:11px}
.pill-audit.warn{color:var(--amber);border-color:color-mix(in srgb,var(--amber) 32%,transparent);
  background:color-mix(in srgb,var(--amber) 10%,transparent)}

/* 学习页草稿（待校对）标记 */
.tag.draft{color:var(--amber);border-color:color-mix(in srgb,var(--amber) 38%,transparent);
  background:color-mix(in srgb,var(--amber) 12%,transparent);font-size:11px}
.draft-note{display:flex;gap:8px;align-items:baseline;flex-wrap:wrap;margin:12px 0 2px;padding:9px 12px;
  border:1px solid color-mix(in srgb,var(--amber) 34%,var(--line));border-left-width:3px;
  border-radius:8px;background:color-mix(in srgb,var(--amber) 8%,transparent);font-size:12.5px;line-height:1.7}
.draft-note b{color:var(--amber);flex:none}
.draft-note span{color:var(--muted)}
.draft-note code{font-size:11.5px}

/* ==================== 校对工作台 / 导入真题 ==================== */
.tag.done{color:var(--green);background:color-mix(in srgb,var(--green) 12%,transparent);border-color:color-mix(in srgb,var(--green) 34%,transparent)}
.rv-sum .rv-kpis{display:flex;gap:26px;flex-wrap:wrap}
.rv-kpi{display:flex;flex-direction:column;gap:2px}
.rv-kpi b{font-size:26px;line-height:1.1}
.rv-kpi span{font-size:11.5px;color:var(--muted)}
.rv-bar{height:7px;border-radius:99px;background:var(--card2);border:1px solid var(--line);margin:14px 0 16px;overflow:hidden}
.rv-bar i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--green));border-radius:99px;transition:width .25s}
.rv-sum .actions{display:flex;gap:10px;flex-wrap:wrap}
.rv-hint{font-size:11.5px;color:var(--muted);line-height:1.8;margin:12px 0 0}
.rv-hint code,.im-steps code{font-size:11.5px;background:var(--card2);border:1px solid var(--line);border-radius:5px;padding:1px 5px}
.rv-filters{margin:18px 0 12px;display:flex;flex-direction:column;gap:10px}
.rv-filters input{padding:9px 12px;border-radius:10px;border:1px solid var(--line);background:var(--card);color:var(--text);font:inherit;font-size:13px}
.rv-filters input:focus{border-color:var(--accent);outline:none}
.rv-filters .hint{font-size:11.5px;color:var(--muted)}
.rv-list{display:flex;flex-direction:column;gap:8px}
.rv-item{display:flex;align-items:center;gap:12px;padding:11px 14px;border:1px solid var(--line);border-radius:12px;background:var(--card);flex-wrap:wrap}
.rv-item.done{opacity:.72;background:var(--card2)}
.rv-main{display:flex;flex-direction:column;gap:3px;min-width:0;flex:1}
.rv-main b{font-size:13.5px;font-weight:600}
.rv-meta{font-size:11px;color:var(--muted)}
.rv-acts{display:flex;gap:8px;flex-wrap:wrap}
.rv-acts .btn{padding:6px 11px;font-size:12px}
.im-panel .im-steps{margin:0 0 14px;padding-left:20px;font-size:12.5px;line-height:1.95;color:var(--muted)}
.im-panel .actions{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:12px}
.im-panel textarea{width:100%;border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:var(--card2);color:var(--text);
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12px;line-height:1.65;resize:vertical;margin-bottom:12px}
.im-panel textarea:focus{border-color:var(--accent);outline:none}
.im-row{display:flex;align-items:center;gap:12px;justify-content:space-between;padding:9px 12px;border:1px solid var(--line);border-radius:11px;background:var(--card);margin-bottom:8px;flex-wrap:wrap}
.im-msg{display:flex;flex-direction:column;gap:10px;margin-top:14px}
.im-block{border:1px solid var(--line);border-radius:11px;padding:11px 14px;background:var(--card2);font-size:12.5px;line-height:1.8}
.im-block ul{margin:6px 0 0;padding-left:20px;color:var(--muted)}
.im-block.bad{border-color:color-mix(in srgb,var(--red,#dc2626) 34%,transparent);background:color-mix(in srgb,var(--red,#dc2626) 7%,transparent)}
.im-block.good{border-color:color-mix(in srgb,var(--green) 34%,transparent);background:color-mix(in srgb,var(--green) 8%,transparent)}
.im-block.warn{border-color:color-mix(in srgb,var(--amber) 36%,transparent);background:color-mix(in srgb,var(--amber) 8%,transparent)}
.pill-local{color:var(--accent);border-color:color-mix(in srgb,var(--accent) 34%,transparent);background:color-mix(in srgb,var(--accent) 10%,transparent)}

/* 拍照建卷 */
.im-tabs{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:14px}
.im-fields{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:10px;margin:12px 0 14px}
.im-fields label{display:flex;flex-direction:column;gap:5px;font-size:11.5px;color:var(--muted)}
.im-fields input,.im-fields select{padding:8px 10px;border-radius:9px;border:1px solid var(--line);background:var(--card2);color:var(--text);font-size:13px;outline:none}
.im-fields input:focus,.im-fields select:focus{border-color:var(--accent)}
.photo-thumbs{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:12px}
.photo-thumbs figure{position:relative;margin:0;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--card2)}
.photo-thumbs img{display:block;width:120px;height:90px;object-fit:cover}
.photo-thumbs button{position:absolute;top:4px;right:4px;width:20px;height:20px;border-radius:50%;background:rgba(15,23,42,.72);color:#fff;font-size:12px;line-height:1}
.photo-list-head,.photo-item-row{display:grid;grid-template-columns:34px 70px 1fr 26px;gap:8px;align-items:center}
.photo-list-head{font-size:11px;color:var(--muted);padding:0 2px 6px}
.photo-item-row{padding:5px 0;border-top:1px solid var(--line)}
.pi-no{font-size:12px;color:var(--muted);text-align:center}
.pi-score{padding:6px 8px;border-radius:8px;border:1px solid var(--line);background:var(--card2);color:var(--text);font-size:13px;text-align:center;outline:none}
.pi-score:focus{border-color:var(--accent)}
.pi-pid{width:100%;padding:6px 8px;border-radius:8px;border:1px solid var(--line);background:var(--card2);color:var(--text);font-size:12.5px;outline:none}
.photo-sheet{display:flex;flex-direction:column;gap:14px;margin:14px 0}
.photo-page{margin:0;border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--card)}
.photo-page img{display:block;width:100%;height:auto}
.photo-page figcaption{font-size:11px;color:var(--muted);padding:6px 10px;border-top:1px solid var(--line)}
.photo-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:8px}
.photo-row{display:flex;align-items:center;gap:10px;padding:7px 10px;border:1px solid var(--line);border-radius:10px;background:var(--card2)}
.photo-no{font-size:12.5px;font-weight:600;flex:none;min-width:52px}
.photo-score{font-size:11.5px;color:var(--muted);flex:none}
.photo-pts{font-size:11.5px;color:var(--muted);flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.photo-jd{display:flex;gap:6px;flex:none}
.photo-jd .chip{padding:4px 12px}
.photo-jd .chip.bad{background:color-mix(in srgb,var(--red,#dc2626) 14%,transparent);border-color:var(--red,#dc2626);color:var(--red,#dc2626)}
@media (max-width:560px){.photo-list-head,.photo-item-row{grid-template-columns:28px 58px 1fr 22px}}

/* ==================== 授权 / 试用 ==================== */
.point-btn .lock{font-size:9.5px;color:var(--muted);border:1px solid var(--line);border-radius:5px;padding:0 4px;margin-left:6px;flex:none}
.point-btn.locked{opacity:.55}
.lic-bar{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:0 0 16px;padding:10px 14px;border-radius:12px;
  background:color-mix(in srgb,var(--amber,#f59e0b) 10%,transparent);border:1px solid color-mix(in srgb,var(--amber,#f59e0b) 28%,transparent);font-size:13px}
.lic-card{text-align:center;padding:38px 24px;border:1px solid var(--line);border-radius:18px;background:var(--card);box-shadow:var(--shadow)}
.lic-lock{font-size:30px;margin-bottom:10px}
.lic-card h2{font-size:19px;margin-bottom:8px}
.lic-card p{color:var(--muted);font-size:13.5px;line-height:1.7;max-width:440px;margin:0 auto}
.lic-card-actions{display:flex;gap:10px;justify-content:center;margin-top:18px;flex-wrap:wrap}
.lic-state{font-size:13px;color:var(--accent);font-weight:600;margin-top:4px}
.lic-msg{margin-top:10px;padding:9px 12px;border-radius:10px;font-size:12.5px;
  background:color-mix(in srgb,var(--red,#dc2626) 9%,transparent);color:var(--red,#dc2626);border:1px solid color-mix(in srgb,var(--red,#dc2626) 24%,transparent)}
.lic-help{color:var(--muted);font-size:12.5px;line-height:1.7;margin-top:10px}


/* ============ 科目授权门禁 ============ */
.lic-gate{display:grid;place-items:center;min-height:60vh;padding:20px}
.lic-gate-card{width:min(520px,100%);background:var(--card);border:1px solid var(--line);border-radius:18px;padding:26px 24px;text-align:center;box-shadow:0 12px 30px rgba(15,23,42,.06)}
.lic-gate-lock{font-size:30px;line-height:1}
.lic-gate-card h2{margin:10px 0 6px;font-size:19px}
.lic-gate-p{color:var(--muted);font-size:13px;line-height:1.75;margin:0 0 14px}
.lic-gate-others{font-size:12.5px;color:var(--accent);margin:0 0 12px}
.lic-gate-actions{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:16px 0 12px}
.lic-gate-help{color:var(--muted);font-size:11.5px;line-height:1.7;margin:0}
.lic-gate-help code{background:var(--card2);padding:1px 5px;border-radius:5px;font-size:11px}
.lic-gate-side{color:var(--muted);font-size:12px;padding:14px 10px}

/* ==================== 移动端适配 ==================== */
:root{
  --safe-top:env(safe-area-inset-top,0px);
  --safe-bottom:env(safe-area-inset-bottom,0px);
  --safe-left:env(safe-area-inset-left,0px);
  --safe-right:env(safe-area-inset-right,0px);
  --kb:0px;            /* 软键盘高度，由 app.js 写入 */
  --vvh:100vh;         /* 可视视口高度，由 app.js 写入 */
  --topbar-h:calc(64px + var(--safe-top));
}
body{min-height:100vh;min-height:100dvh}
.topbar{padding-left:max(20px,var(--safe-left));padding-right:max(20px,var(--safe-right))}
.layout{height:calc(100vh - var(--topbar-h))}
@supports (height:100dvh){.layout{height:calc(100dvh - var(--topbar-h))}}
.main{padding-bottom:calc(70px + var(--safe-bottom))}

/* 长公式与题图：横向滚动，不撑破卡片 */
.katex-display{overflow-x:auto;overflow-y:hidden;padding:2px 0}
.fc-formula,.formula-row,.q-figure{overflow-x:auto;overflow-y:hidden}
.q-stem,.fg-stem{overflow-wrap:anywhere}

/* 移动端目录抽屉遮罩 */
.nav-scrim{display:none;position:fixed;inset:0;z-index:65;background:rgba(8,13,26,.46);
  opacity:0;pointer-events:none;transition:opacity .2s}
.nav-scrim.on{opacity:1;pointer-events:auto}
body.nav-open{overflow:hidden}

@media (max-width:900px){
  .topbar{height:var(--topbar-h);padding-top:var(--safe-top)}
  .brand-text b{max-width:36vw;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
  .icon-btn{width:44px;height:44px;border-radius:12px;font-size:17px}
  .tabs{padding-bottom:calc(6px + var(--safe-bottom));transform:translateY(var(--kb));transition:transform .18s}
  .tabs button{min-height:44px;font-size:12.5px;padding:7px 4px;display:flex;flex-direction:column;
    align-items:center;justify-content:center;gap:1px}
  .layout{height:calc(100vh - var(--topbar-h))}
  .sidebar{top:var(--topbar-h);bottom:calc(56px + var(--safe-bottom));width:min(310px,86vw);padding-left:var(--safe-left)}
  .nav-scrim{display:block}
  .main{padding-bottom:calc(92px + var(--safe-bottom))}
  .btn{min-height:42px;display:inline-flex;align-items:center;justify-content:center}
  .rv-acts .btn,.im-row .btn{min-height:38px}
  .chip,.why-chip{min-height:36px;display:inline-flex;align-items:center}
  .tiny-btn{min-width:34px;min-height:34px}
  .sheet-cell{width:40px;height:40px;font-size:13px}
  .point-btn{min-height:44px;font-size:13px}
  .book-btn{min-height:44px}
  .chapter-btn{min-height:40px}
  .link-btn{min-height:40px;display:inline-flex;align-items:center}
  .search input,.plan-field input,.im-fields input,.im-fields select,.rv-filters input,
  .paper-text,.modal input,.modal textarea,.modal select{font-size:16px}
  .modal{max-height:calc(var(--vvh,100vh) - 20px)}
  .modal-body{max-height:calc(var(--vvh,100vh) - 150px)}
  .ai-fab{bottom:calc(74px + var(--safe-bottom) + var(--kb))}
  .ai-panel{bottom:var(--kb)}
  .photo-thumbs img{width:96px;height:72px}
  .photo-list-head,.photo-item-row{grid-template-columns:24px 56px minmax(0,1fr) 30px}
  /* 书册横幅：三栏在窄屏挤成一条，改成两行 */
  .book-banner{flex-wrap:wrap;gap:12px;padding:16px 18px;align-items:center}
  .book-banner .bb-icon{width:46px;height:46px;border-radius:13px;font-size:20px}
  .book-banner > div:nth-child(2){flex:1 1 120px;min-width:0}
  .book-banner h2{font-size:17px;line-height:1.35}
  .book-banner .bb-right{margin-left:0;width:100%;text-align:left;min-width:0;
    display:flex;align-items:center;gap:10px;flex-wrap:wrap}
  .book-banner .bb-right .mini-bar{flex:1 1 90px;margin-top:0}
  .section-head{flex-wrap:wrap;gap:8px 12px;margin:24px 0 12px}
  .section-head .rule{display:none}
  .book-tab{padding:8px 13px;min-height:42px}
  /* 窄屏横向滚动条隐藏，视觉更干净 */
  .learn-nav,.ans-wrap,.katex-display,.fc-formula,.formula-row,.q-figure{scrollbar-width:none;-webkit-overflow-scrolling:touch}
  .learn-nav::-webkit-scrollbar,.ans-wrap::-webkit-scrollbar,.katex-display::-webkit-scrollbar,
  .fc-formula::-webkit-scrollbar,.formula-row::-webkit-scrollbar,.q-figure::-webkit-scrollbar{display:none}
  .learn-nav{padding-bottom:calc(8px + var(--safe-bottom))}
  .hstat b{font-size:20px;line-height:1.15}
}
@supports (height:100dvh){
  @media (max-width:900px){.layout{height:calc(100dvh - var(--topbar-h))}}
}