:root{
  --bg:#F5F6F2; --surface:#FFFFFF; --surface-2:#EEF0EA;
  --ink:#1A1F2B; --ink-soft:#616A7D; --line:#E3E6DF;
  --accent:#2E45C4; --accent-soft:#E8EBFA;
  --ok:#1B7A47; --ok-soft:#E4F2E9; --ok-line:#9FD3B4;
  --bad:#C5362E; --bad-soft:#FAE7E5; --bad-line:#E8A9A4;
  --warn:#9A6B12;
  --shadow:0 1px 2px rgba(20,25,40,.05),0 6px 18px rgba(20,25,40,.06);
  --radius:14px;
  --font:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Noto Sans SC","Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"JetBrains Mono","SFMono-Regular","SF Mono",Menlo,Consolas,"Liberation Mono",monospace;
  --c-kw:#9333C0; --c-str:#1B7A47; --c-num:#B5530F; --c-com:#8A93A3; --c-fn:#2E45C4; --c-ty:#0E7490;
}
[data-theme="dark"]{
  --bg:#10141B; --surface:#161B23; --surface-2:#1E2530;
  --ink:#E6E9F0; --ink-soft:#98A1B2; --line:#28303C;
  --accent:#8AA0FF; --accent-soft:#1E2742;
  --ok:#54C088; --ok-soft:#15281E; --ok-line:#2E5C42;
  --bad:#F0746B; --bad-soft:#2C1816; --bad-line:#5C322E;
  --warn:#D6A24A;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 22px rgba(0,0,0,.4);
  --c-kw:#C792EA; --c-str:#7FD89B; --c-num:#E0A06A; --c-com:#6B7686; --c-fn:#8AA0FF; --c-ty:#5CC9D8;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;overscroll-behavior-y:none}
body{background:var(--bg);color:var(--ink);font-family:var(--font);-webkit-font-smoothing:antialiased;line-height:1.6}
button{font-family:inherit;cursor:pointer}
input,select,textarea{font-family:inherit;font-size:15px}
.topbar{position:sticky;top:0;z-index:30;background:color-mix(in srgb,var(--bg) 86%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.topbar-in{max-width:860px;margin:0 auto;padding:12px 18px;display:flex;align-items:center;gap:12px}
.brand{display:flex;align-items:baseline;gap:9px;font-weight:700;letter-spacing:-.02em;font-size:18px}
.brand .dot{width:9px;height:9px;border-radius:2px;background:var(--accent);transform:rotate(45deg);display:inline-block;position:relative;top:-1px}
.brand small{font-weight:500;color:var(--ink-soft);font-size:12px;letter-spacing:0}
.spacer{flex:1}
.icon-btn{width:38px;height:38px;border-radius:10px;border:1px solid var(--line);background:var(--surface);color:var(--ink);display:grid;place-items:center;font-size:17px;transition:.15s}
.icon-btn:hover{border-color:var(--accent);color:var(--accent)}
.tabs{max-width:860px;margin:0 auto;padding:10px 12px 0;display:flex;gap:6px;overflow-x:auto;scrollbar-width:none}
.tabs::-webkit-scrollbar{display:none}
.tab{flex:0 0 auto;padding:8px 14px;border-radius:999px;border:1px solid transparent;background:transparent;color:var(--ink-soft);font-size:14px;font-weight:600;white-space:nowrap;transition:.15s}
.tab:hover{color:var(--ink)}
.tab.active{background:var(--accent-soft);color:var(--accent);border-color:color-mix(in srgb,var(--accent) 30%,transparent)}
.tab .badge{margin-left:6px;font-size:11px;background:var(--bad);color:#fff;border-radius:999px;padding:1px 6px;font-weight:700}
.wrap{max-width:860px;margin:0 auto;padding:18px 18px 90px}
.toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:flex-end;margin-bottom:18px}
.field{display:flex;flex-direction:column;gap:4px}
.field label{font-size:11px;color:var(--ink-soft);font-weight:600;letter-spacing:.02em;text-transform:uppercase}
select,.inp{height:40px;padding:0 12px;border-radius:10px;border:1px solid var(--line);background:var(--surface);color:var(--ink);min-width:120px}
select:focus,.inp:focus,textarea:focus{outline:2px solid color-mix(in srgb,var(--accent) 45%,transparent);outline-offset:1px;border-color:var(--accent)}
.btn{height:40px;padding:0 18px;border-radius:10px;border:1px solid var(--accent);background:var(--accent);color:#fff;font-weight:700;font-size:14px;transition:.15s;display:inline-flex;align-items:center;gap:7px}
.btn:hover{filter:brightness(1.06)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn.ghost{background:transparent;color:var(--accent)}
.btn.subtle{background:var(--surface);color:var(--ink);border-color:var(--line)}
.btn.subtle:hover{border-color:var(--accent);color:var(--accent)}
textarea{width:100%;min-height:160px;padding:12px 14px;border-radius:12px;border:1px solid var(--line);background:var(--surface);color:var(--ink);resize:vertical;line-height:1.6}
textarea.code{font-family:var(--mono);font-size:13.5px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:22px 22px 20px}
.q-head{display:flex;align-items:center;gap:8px;margin-bottom:14px;flex-wrap:wrap}
.chip{font-size:12px;font-weight:600;padding:3px 10px;border-radius:999px;background:var(--surface-2);color:var(--ink-soft)}
.chip.accent{background:var(--accent-soft);color:var(--accent)}
.diff{letter-spacing:1px;color:var(--warn);font-size:12px}
.star{margin-left:auto;width:34px;height:34px;border-radius:9px;border:1px solid var(--line);background:transparent;color:var(--ink-soft);font-size:16px}
.star.on{color:var(--warn);border-color:var(--warn)}
.passage{background:var(--surface-2);border-left:3px solid var(--accent);border-radius:0 10px 10px 0;padding:12px 16px;margin-bottom:16px;font-size:14.5px;color:var(--ink-soft)}
.stem{font-size:17px;font-weight:600;margin-bottom:16px;line-height:1.7}
.opt{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border:1px solid var(--line);border-radius:11px;margin-bottom:9px;background:var(--surface);transition:.12s;cursor:pointer;position:relative}
.opt:hover{border-color:var(--accent)}
.opt .key{flex:0 0 26px;height:26px;border-radius:7px;border:1px solid var(--line);display:grid;place-items:center;font-weight:700;font-size:13px;color:var(--ink-soft)}
.opt.sel{border-color:var(--accent);background:var(--accent-soft)}
.opt.sel .key{background:var(--accent);color:#fff;border-color:var(--accent)}
.opt.correct{border-color:var(--ok-line);background:var(--ok-soft)}
.opt.correct .key{background:var(--ok);color:#fff;border-color:var(--ok)}
.opt.wrong{border-color:var(--bad-line);background:var(--bad-soft)}
.opt.wrong .key{background:var(--bad);color:#fff;border-color:var(--bad)}
.opt .mark{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-weight:800;font-size:15px}
.opt.correct .mark{color:var(--ok)}
.opt.wrong .mark{color:var(--bad)}
.opt.disabled{cursor:default}
.opt-body{flex:1;padding-top:1px}
.tf-row{display:flex;gap:12px;margin-bottom:6px}
.tf{flex:1;padding:14px;text-align:center;border:1px solid var(--line);border-radius:11px;background:var(--surface);font-weight:700;transition:.12s;cursor:pointer}
.tf.sel{border-color:var(--accent);background:var(--accent-soft);color:var(--accent)}
.tf.correct{border-color:var(--ok-line);background:var(--ok-soft);color:var(--ok)}
.tf.wrong{border-color:var(--bad-line);background:var(--bad-soft);color:var(--bad)}
.verdict{display:flex;align-items:center;gap:9px;font-weight:700;margin:16px 0 10px;flex-wrap:wrap}
.verdict.ok{color:var(--ok)} .verdict.bad{color:var(--bad)}
.verdict .tag{font-size:12px;padding:2px 10px;border-radius:999px}
.verdict.ok .tag{background:var(--ok-soft)} .verdict.bad .tag{background:var(--bad-soft)}
.ref{background:var(--surface-2);border-radius:11px;padding:14px 16px;margin-top:10px}
.ref h5{margin:0 0 6px;font-size:12px;letter-spacing:.04em;text-transform:uppercase;color:var(--ink-soft)}
.selfgrade{display:flex;gap:10px;margin:14px 0 4px;align-items:center;flex-wrap:wrap}
.selfgrade .q{font-size:13px;color:var(--ink-soft);margin-right:2px}
.note-toggle{margin-top:12px;font-size:13px;color:var(--accent);background:none;border:none;padding:0;font-weight:600}
.q-actions{display:flex;gap:10px;margin-top:18px;flex-wrap:wrap}
.rich :is(p){margin:.2em 0}
.rich pre{background:var(--surface-2);border:1px solid var(--line);border-radius:10px;padding:12px 14px;overflow:auto;margin:.5em 0}
.rich code{font-family:var(--mono);font-size:13.5px}
.rich :not(pre)>code{background:var(--surface-2);padding:1px 6px;border-radius:6px;font-size:.9em}
.rich pre code{display:block;line-height:1.55;background:none;padding:0}
.hljs-keyword,.hljs-built_in{color:var(--c-kw)} .hljs-string{color:var(--c-str)}
.hljs-number,.hljs-literal{color:var(--c-num)} .hljs-comment{color:var(--c-com);font-style:italic}
.hljs-title,.hljs-title.function_{color:var(--c-fn)} .hljs-type,.hljs-class .hljs-title{color:var(--c-ty)}
.hljs-attr,.hljs-attribute{color:var(--c-ty)}
.empty{text-align:center;color:var(--ink-soft);padding:60px 20px}
.empty .big{font-size:40px;margin-bottom:10px;opacity:.5}
.spin{display:inline-block;width:18px;height:18px;border:2px solid var(--line);border-top-color:var(--accent);border-radius:50%;animation:sp .7s linear infinite;vertical-align:-3px}
@keyframes sp{to{transform:rotate(360deg)}}
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:20px}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:16px}
.stat .n{font-size:26px;font-weight:800;letter-spacing:-.02em}
.stat .l{font-size:12px;color:var(--ink-soft);margin-top:2px}
.subj-row{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin-bottom:10px}
.subj-row .top{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;font-weight:600;gap:10px;flex-wrap:wrap}
.bar{height:8px;background:var(--surface-2);border-radius:99px;overflow:hidden}
.bar>span{display:block;height:100%;background:var(--ok);border-radius:99px;transition:width .5s}
.bar.accent>span{background:var(--accent)}
.ocr-panel{background:var(--surface-2);border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin:12px 0}
.ocr-panel .top{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;align-items:center;margin-bottom:9px}
.ocr-panel .pct{font-family:var(--mono);font-weight:800;color:var(--accent)}
.muted{color:var(--ink-soft);font-size:13px}
.mock-bar{position:sticky;top:62px;z-index:20;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:10px 16px;display:flex;align-items:center;gap:14px;margin-bottom:16px;box-shadow:var(--shadow);flex-wrap:wrap}
.timer{font-family:var(--mono);font-weight:700;font-size:18px}
.timer.warn{color:var(--bad)}
.stamp{width:128px;height:128px;border-radius:50%;border:4px solid var(--accent);color:var(--accent);display:grid;place-items:center;transform:rotate(-9deg);margin:6px auto 14px;box-shadow:inset 0 0 0 2px color-mix(in srgb,var(--accent) 25%,transparent)}
.stamp.ok{border-color:var(--ok);color:var(--ok)} .stamp.bad{border-color:var(--bad);color:var(--bad)}
.stamp .s{font-size:34px;font-weight:800;line-height:1} .stamp .u{font-size:11px;letter-spacing:.1em;margin-top:3px}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:10px;overflow:hidden}
.seg button{padding:8px 16px;background:var(--surface);border:none;color:var(--ink-soft);font-weight:600;font-size:14px}
.seg button.on{background:var(--accent);color:#fff}
.toast{position:fixed;left:50%;bottom:26px;transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:11px 20px;border-radius:999px;font-size:14px;font-weight:600;z-index:50;box-shadow:var(--shadow);max-width:90vw}
.stealth{position:fixed;inset:0;z-index:9999;background:var(--bg);display:grid;place-items:center;cursor:default}
.stealth-box{text-align:center;color:var(--ink-soft)}
.stealth-box .spin{width:26px;height:26px;border-width:3px;margin-bottom:14px}
.toast.err{background:var(--bad);color:#fff}
.hint{font-size:13px;color:var(--ink-soft);background:var(--surface-2);border-radius:10px;padding:10px 14px;margin-top:10px;line-height:1.6}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
a{color:var(--accent)}
@media(max-width:560px){
  .wrap{padding:14px 12px 90px}
  .card{padding:18px 15px}
  .stem{font-size:16px}
  select,.inp{min-width:0;flex:1}
}
/* —— 教材阅读 Books 美化 —— */
.bk-shelf{margin-bottom:20px}
.bk-shelf-label{font-size:12px;font-weight:700;letter-spacing:.04em;color:var(--ink-soft);margin:0 0 10px;display:flex;align-items:center;gap:10px}
.bk-shelf-label::after{content:"";flex:1;height:1px;background:var(--line)}
.bk-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.bk-card{position:relative;text-align:left;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px 16px 14px 20px;cursor:pointer;transition:.16s;display:flex;flex-direction:column;gap:10px;min-height:88px}
.bk-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:var(--shadow)}
.bk-card.on{border-color:var(--accent);background:var(--accent-soft)}
.bk-card .spine{position:absolute;left:0;top:12px;bottom:12px;width:4px;border-radius:0 4px 4px 0;background:var(--accent);opacity:.3}
.bk-card.on .spine{opacity:1}
.bk-card .t{font-weight:700;font-size:14.5px;line-height:1.4;color:var(--ink);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.bk-card .m{font-size:12px;color:var(--ink-soft);margin-top:auto}
.bk-reader{display:grid;grid-template-columns:208px 1fr;gap:16px;align-items:start;margin-top:20px}
.bk-reader.toc-collapsed{grid-template-columns:1fr}
.bk-reader.toc-collapsed .bk-toc{display:none}
.bk-toctoggle{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:var(--surface);color:var(--ink-soft);border-radius:8px;padding:6px 11px;font-size:13px;cursor:pointer;white-space:nowrap}
.subj-edit{padding:10px 0;border-bottom:1px solid var(--line)}
.subj-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.subj-code{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:12px;color:var(--ink-soft);background:var(--surface-2);padding:3px 8px;border-radius:6px;min-width:78px;text-align:center}
.subj-add{margin-top:14px;padding-top:12px}
.bank-toolbar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin:6px 2px 14px;font-size:13px}
.bank-check{display:inline-flex;align-items:center;gap:6px;cursor:pointer}
.bank-row{display:flex;align-items:flex-start;gap:12px;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-bottom:8px;transition:.12s}
.bank-row.sel{border-color:var(--accent);background:var(--accent-soft)}
.bank-rowck{margin-top:3px;flex:none}
.bank-main{flex:1;min-width:0}
.bank-meta{display:flex;align-items:center;gap:8px;margin-bottom:6px}
.bank-meta .tag{background:var(--accent-soft);color:var(--accent);font-size:12px;font-weight:600;padding:2px 8px;border-radius:6px}
.bank-meta .tag2{background:var(--surface-2);color:var(--ink-soft);font-size:12px;padding:2px 8px;border-radius:6px}
.bank-stem{font-size:14.5px;line-height:1.6;color:var(--ink);max-height:3.2em;overflow:hidden;position:relative}
.bank-stem::after{content:'';position:absolute;right:0;bottom:0;width:40px;height:1.6em;background:linear-gradient(90deg,transparent,var(--surface))}
.bank-row.sel .bank-stem::after{background:linear-gradient(90deg,transparent,var(--accent-soft))}
.bank-side{display:flex;flex-direction:column;gap:6px;flex:none}
.btn.xs,.bk-del.xs{font-size:12px;padding:4px 10px}
.modal-mask{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:80;display:flex;align-items:center;justify-content:center;padding:20px}
.modal{background:var(--surface);border:1px solid var(--line);border-radius:14px;width:min(640px,100%);max-height:88vh;display:flex;flex-direction:column;box-shadow:0 20px 60px rgba(0,0,0,.4)}
.modal-h{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;border-bottom:1px solid var(--line);font-size:15px}
.modal-b{padding:16px 18px;overflow:auto}
.modal-b .lbl{display:block;font-size:12.5px;color:var(--ink-soft);margin-bottom:5px}
.modal-b textarea.inp{width:100%;font-family:var(--font);font-size:14px;line-height:1.6;resize:vertical}
.modal-b .prev-box{margin-top:14px;padding:12px;border:1px dashed var(--line);border-radius:10px;background:var(--surface-2)}
.prev-list{display:flex;flex-direction:column;gap:10px}
.prev-item{display:flex;gap:10px;padding:12px;border:1px solid var(--line);border-radius:11px;background:var(--surface)}
.prev-item.noans{border-color:color-mix(in srgb,var(--bad) 45%,var(--line))}
.prev-item.off{opacity:.5}
.prev-ck{flex:none;padding-top:2px}
.prev-ck input{width:18px;height:18px}
.prev-body{flex:1;min-width:0}
.prev-meta{display:flex;align-items:center;gap:8px;margin-bottom:6px;flex-wrap:wrap}
.prev-q{display:flex;gap:8px;margin-top:6px}
.prev-lab{flex:none;font-size:11px;font-weight:700;color:var(--muted);background:var(--surface-2);border:1px solid var(--line);border-radius:6px;padding:2px 6px;height:fit-content}
.prev-lab.ans{color:var(--ok);border-color:color-mix(in srgb,var(--ok) 45%,var(--line))}
.prev-q .rich{font-size:14px;line-height:1.6;flex:1;min-width:0;overflow-x:auto}
.prev-opts{display:flex;flex-wrap:wrap;gap:6px 14px;margin-top:6px;font-size:13.5px;color:var(--ink)}
.prev-opt b{color:var(--accent)}
.modal-f .muted{margin-right:auto}
.modal-f{display:flex;justify-content:flex-end;gap:10px;padding:14px 18px;border-top:1px solid var(--line)}
.bank-row{background:var(--surface);border:1px solid var(--line)}
.bk-toctoggle:hover{background:var(--surface-2);color:var(--ink)}
.bk-toc{position:sticky;top:74px;max-height:calc(100vh - 92px);overflow:auto;background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:14px}
.bk-toc h4{margin:0;font-size:14px;font-weight:700;display:flex;justify-content:space-between;align-items:center}
.bk-toc .tip{font-size:11.5px;color:var(--ink-soft);margin:5px 0 12px}
.bk-toc .toc-close{display:none;border:none;background:transparent;color:var(--ink-soft);font-size:20px;line-height:1;cursor:pointer;padding:0 4px}
.bk-toc-item{padding:8px 10px;border-radius:8px;margin-bottom:2px;font-size:13px;line-height:1.45;color:var(--ink);cursor:pointer;transition:.12s;border-left:2px solid transparent;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bk-toc-item:hover{background:var(--surface-2)}
.bk-toc-item.on{background:var(--accent-soft);color:var(--accent);border-left-color:var(--accent);font-weight:600}
.bk-toc-backdrop{display:none}
@media(max-width:860px){
  .bk-reader,.bk-reader.toc-collapsed{grid-template-columns:1fr}
  .bk-reader .bk-toc{display:block;position:fixed;left:0;top:0;bottom:0;height:100%;max-height:100%;width:84%;max-width:330px;z-index:60;border-radius:0 14px 14px 0;transform:translateX(-100%);transition:transform .26s ease;margin:0;box-shadow:0 10px 40px rgba(0,0,0,.35)}
  .bk-reader.toc-open .bk-toc{transform:translateX(0)}
  .bk-toc .toc-close{display:block}
  .bk-reader.toc-open .bk-toc-backdrop{display:block;position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:55}
  .bk-toc-item{font-size:14px;padding:11px 12px}
}
.bk-page{background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);overflow:hidden}
.bk-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding:14px 20px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--surface-2) 45%,var(--surface))}
.bk-bar .ttl{font-weight:700;font-size:16.5px;line-height:1.35}
.bk-bar .sub{font-size:12.5px;color:var(--ink-soft);margin-top:2px}
.bk-nav{display:inline-flex;border:1px solid var(--line);border-radius:9px;overflow:hidden;background:var(--surface)}
.bk-nav button{height:34px;padding:0 14px;background:transparent;border:none;color:var(--ink);font-weight:600;font-size:13.5px;transition:.12s}
.bk-nav button:disabled{color:var(--ink-soft);opacity:.45;cursor:default}
.bk-nav button:not(:disabled):hover{background:var(--accent-soft);color:var(--accent)}
.bk-nav button+button{border-left:1px solid var(--line)}
.bk-jump{height:34px;width:74px;padding:0 10px;border-radius:8px;border:1px solid var(--line);background:var(--surface);color:var(--ink);min-width:0}
.bk-mini{height:34px;padding:0 10px;border-radius:8px;min-width:0}
.bk-del{height:34px;padding:0 12px;border-radius:8px;border:1px solid var(--line);background:var(--surface);color:#c0392b;font-weight:600;font-size:13px;transition:.12s}
.bk-del:hover{border-color:#c0392b;background:color-mix(in srgb,#c0392b 8%,var(--surface))}
.bk-body{padding:30px 40px 36px;max-width:1040px;margin:0 auto}
.bk-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:240px;padding:40px}
.bk-loadbar{width:200px;max-width:60%;height:4px;border-radius:3px;background:var(--surface-2);overflow:hidden;position:relative}
.bk-loadbar::after{content:'';position:absolute;left:-40%;top:0;bottom:0;width:40%;border-radius:3px;background:var(--accent);animation:bkload 1s ease-in-out infinite}
@keyframes bkload{0%{left:-40%}100%{left:100%}}
.bk-body .summary{font-size:13px;color:var(--accent);font-weight:600;margin:0 0 16px;padding-left:12px;border-left:3px solid var(--accent)}
.bk-body .rich{font-size:16px;line-height:1.95;color:var(--ink)}
.bk-body .rich img{max-width:min(100%,560px);height:auto;display:block;margin:16px auto 4px;border:1px solid var(--line);border-radius:8px;background:#fff;padding:6px}
.bk-body .rich figure.fig{margin:16px 0;text-align:center}
.bk-body .rich figure.fig img{margin:0 auto 4px}
.bk-body .rich figure.fig figcaption,.bk-body .rich .figcap{text-align:center;font-size:13px;color:var(--ink-soft);margin:2px 0 4px}
.bk-body .rich ol{padding-left:1.9em;margin:12px 0}
.bk-body .rich ol>li{margin:10px 0;padding-left:2px}
.bk-body .rich ol>li::marker{font-weight:700;color:var(--ink)}
.bk-body .rich .mathwrap{display:block;max-width:100%;overflow:hidden;margin:6px 0}
.bk-body .rich .mathwrap .katex{white-space:nowrap}
.bk-body .rich .katex-display{overflow:hidden;max-width:100%;text-align:left;padding:4px 0 8px}
.bk-body .rich .katex-display>.katex{white-space:nowrap}
.rich .katex-display{overflow:hidden;max-width:100%}
.bk-foot{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:16px 20px;border-top:1px solid var(--line)}
@media(max-width:600px){.bk-body{padding:18px 16px 22px}.bk-body .rich{font-size:15px;line-height:1.85}}
/* —— 沉浸式阅读（番茄/七猫风格：可调字号、阅读主题、点击/滑动翻篇）—— */
.reader{position:fixed;inset:0;z-index:200;display:flex;flex-direction:column;background:var(--rbg);color:var(--rink);-webkit-tap-highlight-color:transparent}
.reader.t-paper{--rbg:#f6f5f1;--rink:#2c2a27;--rsoft:#9a978f;--rline:#e6e3db;--racc:#b06a3a}
.reader.t-sepia{--rbg:#ecdcc0;--rink:#5b4a32;--rsoft:#a08a64;--rline:#dcc8a4;--racc:#8a5a28}
.reader.t-green{--rbg:#cfe4cf;--rink:#2e3f30;--rsoft:#6b8a6e;--rline:#b7d3b7;--racc:#2f6b3a}
.reader.t-night{--rbg:#16161a;--rink:#b6b6b2;--rsoft:#6f6f74;--rline:#2a2a31;--racc:#c98a52}
.reader .r-scroll{flex:1;overflow-y:auto;overflow-x:hidden;-webkit-overflow-scrolling:touch;position:relative}
.reader .r-wrap{max-width:740px;margin:0 auto;padding:60px 26px 116px}
.reader .r-head{margin:0 0 22px}
.reader .r-head .rt{font-size:calc(var(--rfs,19px) + 4px);font-weight:700;line-height:1.4}
.reader .r-head .rs{font-size:13px;color:var(--rsoft);margin-top:6px}
.reader .r-head .rsum{font-size:13.5px;color:var(--racc);font-weight:600;margin-top:12px;padding-left:12px;border-left:3px solid var(--racc)}
.reader .rich{font-size:var(--rfs,19px);line-height:var(--rlh,1.9);color:var(--rink)}
.reader.serif .r-wrap{font-family:"Songti SC","Noto Serif SC","Source Han Serif SC",Georgia,"Times New Roman",serif}
.reader .rich p{margin:0 0 1em}
.reader .rich img{max-width:100%;height:auto;display:block;margin:18px auto;border-radius:8px;background:#fff;padding:6px;border:1px solid var(--rline)}
.reader .rich a{color:var(--racc)}
.reader .rich h1,.reader .rich h2,.reader .rich h3,.reader .rich h4,.reader .rich strong{color:var(--rink)}
.reader .rich ol,.reader .rich ul{padding-left:1.7em;margin:1em 0}
.reader .rich ol>li,.reader .rich ul>li{margin:.55em 0}
.reader .rich code{background:color-mix(in srgb,var(--rink) 9%,transparent);padding:1px 5px;border-radius:5px;font-size:.92em}
.reader .rich pre{background:color-mix(in srgb,var(--rink) 9%,transparent);padding:12px 14px;border-radius:10px;overflow:auto}
.reader .rich blockquote{border-left:3px solid var(--rline);margin:1em 0;padding:2px 0 2px 14px;color:var(--rsoft)}
.reader .rich .katex-display{overflow-x:auto;overflow-y:hidden;max-width:100%;text-align:left;padding:4px 0 8px}
.reader .rich .mathwrap{display:block;max-width:100%;overflow-x:auto;margin:6px 0}
.reader .rich .figcap,.reader .rich figure.fig figcaption{text-align:center;font-size:13px;color:var(--rsoft)}
.reader .r-top,.reader .r-bot{position:absolute;left:0;right:0;background:color-mix(in srgb,var(--rbg) 90%,transparent);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);z-index:6;transition:transform .26s ease}
.reader .r-top{top:0;display:flex;align-items:center;gap:8px;padding:11px 12px;border-bottom:1px solid var(--rline)}
.reader .r-bot{bottom:0;padding:10px 14px calc(12px + env(safe-area-inset-bottom,0px));border-top:1px solid var(--rline)}
.reader.bars-hidden .r-top{transform:translateY(-100%)}
.reader.bars-hidden .r-bot{transform:translateY(100%)}
.reader .r-top .rttl{flex:1;min-width:0;font-weight:600;font-size:14.5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.reader .ricon{min-width:38px;height:38px;border:none;background:transparent;color:var(--rink);font-size:17px;cursor:pointer;border-radius:9px;flex:none;font-weight:600}
.reader .ricon:hover{background:color-mix(in srgb,var(--rink) 8%,transparent)}
.reader .r-bot .rrow{display:flex;align-items:center;gap:10px;max-width:740px;margin:0 auto}
.reader .rbtn{flex:1;height:42px;border:1px solid var(--rline);background:color-mix(in srgb,var(--rink) 4%,transparent);color:var(--rink);border-radius:11px;font-weight:600;font-size:14px;cursor:pointer}
.reader .rbtn:disabled{opacity:.4;cursor:default}
.reader .rprog{font-size:12.5px;color:var(--rsoft);text-align:center;margin-bottom:9px}
.reader .rprog b{color:var(--rink)}
.reader .r-panel{position:absolute;left:0;right:0;bottom:0;z-index:8;background:var(--rbg);border-top:1px solid var(--rline);padding:18px 16px calc(18px + env(safe-area-inset-bottom,0px));transform:translateY(100%);transition:transform .26s ease;box-shadow:0 -10px 40px rgba(0,0,0,.18)}
.reader .r-panel.open{transform:translateY(0)}
.reader .r-panel .pr{display:flex;align-items:center;gap:12px;margin:0 auto 16px;max-width:740px}
.reader .r-panel .pr:last-child{margin-bottom:0}
.reader .r-panel .lbl{width:42px;font-size:13px;color:var(--rsoft);flex:none}
.reader .r-panel .seg{display:flex;gap:8px;flex:1}
.reader .r-panel .seg button{flex:1;min-width:54px;height:38px;border:1px solid var(--rline);background:transparent;color:var(--rink);border-radius:10px;font-size:13.5px;cursor:pointer}
.reader .r-panel .seg button.on{border-color:var(--racc);color:var(--racc);background:color-mix(in srgb,var(--racc) 10%,transparent)}
.reader .r-panel .step{display:flex;align-items:center;gap:10px;flex:1}
.reader .r-panel .step button{width:54px;height:38px;border:1px solid var(--rline);background:transparent;color:var(--rink);border-radius:10px;font-size:15px;cursor:pointer}
.reader .r-panel .step .val{flex:1;text-align:center;font-size:14px;color:var(--rink)}
.reader .r-panel .sw{width:38px;height:38px;border-radius:50%;border:2px solid var(--rline);cursor:pointer;flex:none}
.reader .r-panel .sw.on{border-color:var(--racc);box-shadow:0 0 0 2px var(--rbg) inset}
.reader .r-panel .sw.paper{background:#f6f5f1}.reader .r-panel .sw.sepia{background:#ecdcc0}.reader .r-panel .sw.green{background:#cfe4cf}.reader .r-panel .sw.night{background:#16161a}
.reader .r-panel-backdrop{position:absolute;inset:0;z-index:7}
.reader .r-toc{position:absolute;top:0;bottom:0;left:0;width:84%;max-width:340px;z-index:9;background:var(--rbg);border-right:1px solid var(--rline);transform:translateX(-100%);transition:transform .26s ease;display:flex;flex-direction:column;box-shadow:10px 0 40px rgba(0,0,0,.18)}
.reader .r-toc.open{transform:translateX(0)}
.reader .r-toc h4{margin:0;padding:16px 14px 12px;font-size:15px;display:flex;align-items:center;border-bottom:1px solid var(--rline)}
.reader .r-toc .list{flex:1;overflow:auto;padding:6px}
.reader .r-toc .list>div{padding:12px;border-radius:9px;font-size:14px;color:var(--rink);cursor:pointer;line-height:1.4}
.reader .r-toc .list>div.on{background:color-mix(in srgb,var(--racc) 14%,transparent);color:var(--racc);font-weight:600}
.reader .r-toc-backdrop{position:absolute;inset:0;z-index:8;background:rgba(0,0,0,.4)}
@media(max-width:600px){ .reader .r-wrap{padding:54px 18px 108px} }
/* —— PDF 原书阅读器 —— */
.pdfv{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--surface);box-shadow:var(--shadow);position:relative;margin-top:20px}
.pdfv-drawer{position:absolute;left:0;top:0;bottom:0;width:78%;max-width:300px;z-index:30;background:var(--surface);border-right:1px solid var(--line);box-shadow:0 10px 40px rgba(0,0,0,.35);transform:translateX(-100%);transition:transform .25s ease;display:flex;flex-direction:column}
.pdfv-drawer.open{transform:translateX(0)}
.pdfv-drawer-h{display:flex;align-items:center;padding:14px 14px 10px;border-bottom:1px solid var(--line);font-size:14px}
.pdfv-drawer-h .toc-close{border:none;background:transparent;color:var(--ink-soft);font-size:20px;cursor:pointer}
.pdfv-drawer-list{flex:1;overflow:auto;padding:6px}
.pdfv-drawer-list>div{padding:11px 12px;border-radius:8px;font-size:14px;color:var(--ink);cursor:pointer}
.pdfv-drawer-list>div.on{background:var(--accent-soft);color:var(--accent);font-weight:600}
.pdfv-backdrop{position:absolute;inset:0;background:rgba(0,0,0,.4);z-index:25}
.pdfv-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding:12px 16px;border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--surface-2) 45%,var(--surface))}
.pdfv-bar .ttl{font-weight:700;font-size:15px;flex:1;min-width:140px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.pdfv-zoom{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);border-radius:9px;padding:0 4px;height:34px;background:var(--surface)}
.pdfv-zoom button{width:28px;height:30px;border:none;background:transparent;color:var(--ink);font-size:17px;line-height:1}
.pdfv-zoom span{font-size:12.5px;color:var(--ink-soft);min-width:42px;text-align:center}
.pdfv-body{display:grid;grid-template-columns:144px 1fr;height:min(78vh,880px)}
.pdfv-body.one-col{grid-template-columns:1fr;height:auto}
@media(max-width:700px){
  .pdfv-body{grid-template-columns:84px 1fr;height:min(82vh,900px)}
  .pdfv-body.one-col{grid-template-columns:1fr}
  .pdfv-rail{padding:6px}
  .pdfv-bar{gap:8px;padding:10px 12px}
  .pdfv-bar .ttl{min-width:100%;font-size:14px}
  .pdfv-bar .bk-nav{display:none}
  .pdfv-main{padding:10px;gap:12px}
  .pdfv-foot{position:sticky;bottom:0;z-index:2}
  .pdfv-foot button{padding:9px 18px;font-size:14px}
}
.pdfv-rail{overflow:auto;border-right:1px solid var(--line);padding:10px;background:var(--surface-2)}
.pdfv-thumb{cursor:pointer;border:2px solid transparent;border-radius:8px;padding:4px;margin-bottom:8px;text-align:center;background:var(--surface);transition:.12s}
.pdfv-thumb:hover{border-color:color-mix(in srgb,var(--accent) 40%,transparent)}
.pdfv-thumb.on{border-color:var(--accent)}
.pdfv-thumb canvas{width:100%;height:auto;display:block;border-radius:4px;border:1px solid var(--line);background:#fff;min-height:60px}
.pdfv-thumb span{font-size:11px;color:var(--ink-soft);display:block;margin-top:3px}
.pdfv-main{overflow:auto;overscroll-behavior:contain;display:flex;flex-direction:column;align-items:center;gap:16px;padding:20px;background:var(--surface-2)}
.pdfv-main .pdfv-page{display:flex;justify-content:center;width:100%;flex:0 0 auto}
.pdfv-main .pdfv-page canvas{box-shadow:var(--shadow);background:#fff;border-radius:2px;max-width:100%;height:auto}
.pdfv-single{display:block;overflow-x:auto;-webkit-overflow-scrolling:touch;padding:12px;background:var(--surface-2)}
.pdfv-single canvas{display:block;margin:0 auto;max-width:none;height:auto;box-shadow:var(--shadow);background:#fff}
@media(max-width:900px){ .pdfv-single{padding:6px} }
.pdfv-drawer-jump{font-size:13px;padding:7px 10px;height:auto}
.pdfv-foot{display:flex;align-items:center;justify-content:center;gap:16px;padding:12px 16px;border-top:1px solid var(--line);background:color-mix(in srgb,var(--surface-2) 45%,var(--surface))}
.pdfv-foot button{border:1px solid var(--line);background:var(--surface);color:var(--ink);border-radius:9px;padding:7px 16px;font-size:13px;cursor:pointer}
.pdfv-foot button:disabled{opacity:.4;cursor:not-allowed}
.pdfv-foot button:not(:disabled):hover{border-color:var(--accent);color:var(--accent)}