:root{
  --bg:#f5f6fa; --card:#fff; --ink:#1f2430; --muted:#6b7280; --line:#e5e7eb;
  --pri:#3056d3; --pri-weak:#e8edff; --ok:#16a34a; --ok-weak:#e7f7ec; --bad:#dc2626; --bad-weak:#fdecec;
  --warn:#d97706; --warn-weak:#fff4e0;
  --font-ui:-apple-system,"Segoe UI","PingFang SC","Microsoft YaHei UI","Microsoft YaHei",sans-serif;
  --font-read:"LXGW WenKai Screen",var(--font-ui);
  --font-mono:"Cascadia Mono",Consolas,"Microsoft YaHei UI",monospace;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.65 var(--font-ui)}
a{color:var(--pri);cursor:pointer}
.hidden{display:none!important}
.topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:20px;padding:0 24px;height:56px;background:#162447;color:#fff;box-shadow:0 2px 8px rgba(0,0,0,.15)}
.brand{font-weight:700;font-size:17px;white-space:nowrap}
.brand span{font-weight:400;opacity:.7;margin-left:4px}
#nav{display:flex;gap:4px;flex:1;overflow:auto}
#nav a{color:#cdd6f4;text-decoration:none;padding:6px 12px;border-radius:6px;white-space:nowrap}
#nav a:hover{background:rgba(255,255,255,.08)}
#nav a.active{background:#fff;color:#162447;font-weight:600}
.timerbox{font-variant-numeric:tabular-nums;font-weight:700;background:#fff;color:#162447;padding:4px 12px;border-radius:6px}
.timerbox.low{background:var(--bad);color:#fff}
main{max-width:1180px;margin:0 auto;padding:24px}
h1{font-size:22px;margin:0 0 16px}
h2{font-size:18px;margin:24px 0 12px}
h3{font-size:16px;margin:16px 0 8px}
.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:18px 20px;margin-bottom:16px}
.grid{display:grid;gap:16px}
.g2{grid-template-columns:repeat(2,1fr)} .g3{grid-template-columns:repeat(3,1fr)} .g4{grid-template-columns:repeat(4,1fr)}
@media(max-width:860px){.g2,.g3,.g4{grid-template-columns:1fr}}
.stat{font-size:28px;font-weight:700}
.stat small{font-size:14px;color:var(--muted);font-weight:400;margin-left:4px}
.label{color:var(--muted);font-size:13px}
.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:#fff;color:var(--ink);padding:8px 16px;border-radius:8px;cursor:pointer;font-size:14px;text-decoration:none}
.btn:hover{border-color:var(--pri);color:var(--pri)}
.btn.pri{background:var(--pri);border-color:var(--pri);color:#fff}
.btn.pri:hover{filter:brightness(1.1);color:#fff}
.btn.ok{background:var(--ok);border-color:var(--ok);color:#fff}
.btn.sm{padding:4px 10px;font-size:13px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}
.tag{display:inline-block;font-size:12px;padding:1px 8px;border-radius:10px;background:#eef1f6;color:#475569;margin-right:4px}
.tag.y25{background:#fff1e6;color:#c2410c}
.tag.y26{background:#fde8f0;color:#be123c;font-weight:600}
.y26card{border:2px solid #fda4af;background:linear-gradient(180deg,#fff5f7,#fff)}
.mermaid-box{background:#fff;border:1px solid #e2e8f0;border-radius:8px;padding:12px;margin:10px 0;overflow-x:auto;text-align:center}
.mermaid-box svg{max-width:100%;height:auto}
.mermaid-box details{text-align:left;margin-top:6px;font-size:12px;color:var(--muted)}
.mermaid-box details pre{white-space:pre-wrap}
.pts{border:2px solid #bfdbfe;background:#f8fbff;border-radius:10px;padding:12px 16px;margin:10px 0}
.pts-head{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.pts-hook{font-size:13px;color:#1d4ed8;margin:8px 0 2px}
.pts-list{margin:8px 0 0;padding-left:24px}
.pts-list>li{padding:7px 0;border-bottom:1px dashed var(--line)}
.pts-list>li:last-child{border-bottom:none}
.pt-line{display:flex;gap:8px;align-items:baseline;flex-wrap:wrap}
.pt-t{white-space:nowrap}
.pt-quick{flex:1;min-width:220px}
.pts.recite .pt-quick:not(.shown){filter:blur(6px);cursor:pointer;user-select:none}
.pt-rec{display:none;gap:10px}
.pts.recite .pt-rec{display:inline-flex}
.pt-rec a,.pt-more{font-size:12px;cursor:pointer;color:var(--pri);white-space:nowrap}
.pts-list>li.ok .pt-t{color:var(--ok)}
.pts-list>li.bad .pt-t{color:var(--bad)}
.pt-explain{display:none;margin:8px 0 2px;padding:8px 12px;background:#fff;border-left:3px solid #93c5fd;border-radius:4px;font-size:13.5px}
.pts-list>li.open>.pt-explain{display:block}
.pt-explain p{margin:4px 0}
.pts-terms{margin:8px 0 2px;font-size:13px}
.pts-terms summary{cursor:pointer;color:#1d4ed8}
.pts-terms dl{display:grid;grid-template-columns:max-content 1fr;gap:4px 12px;margin:8px 0 0;background:#fff;border:1px solid var(--line);border-radius:6px;padding:8px 12px}
.pts-terms dt{font-weight:600;color:#0f172a}
.pts-terms dd{margin:0;color:#334155}
.pts.big .pts-list{padding-left:20px}
.pts.big .pts-list>li{padding:10px 0}
.pt-quick.block{display:block;width:100%;margin-top:6px;background:#fff;border:1px solid var(--line);border-radius:6px;padding:6px 12px;font-size:13.5px}
.pt-quick.block table{font-size:13px}
.full-ref{margin-top:14px}
.full-ref>summary{cursor:pointer;font-weight:600;padding:6px 0}
.gates{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:6px 16px;margin-top:12px;font-size:13px;color:var(--muted)}
.gates>div{display:flex;gap:6px}.gates b{margin-left:auto;color:#334155}.gates .ok{color:var(--ok)}
.tag.new{background:#e8f5ff;color:#0369a1}
.tag.ok{background:var(--ok-weak);color:var(--ok)} .tag.bad{background:var(--bad-weak);color:var(--bad)} .tag.warn{background:var(--warn-weak);color:var(--warn)}
.bar{height:10px;background:#eef1f6;border-radius:6px;overflow:hidden}
.bar>i{display:block;height:100%;border-radius:6px}
.kprow{display:grid;grid-template-columns:150px 1fr 110px;gap:10px;align-items:center;padding:5px 0;font-size:14px}
.kprow .n{color:var(--muted);font-size:12px;text-align:right}
select,input[type=date],input[type=number]{padding:7px 10px;border:1px solid var(--line);border-radius:8px;font-size:14px;background:#fff}
textarea{width:100%;min-height:160px;padding:12px;border:1px solid var(--line);border-radius:8px;font:14px/1.7 inherit;font-family:inherit;resize:vertical}
textarea.big{min-height:520px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{border:1px solid var(--line);padding:5px 12px;border-radius:16px;cursor:pointer;user-select:none;background:#fff;font-size:13px}
.chip.on{background:var(--pri);border-color:var(--pri);color:#fff}

/* exam */
.exam-wrap{display:grid;grid-template-columns:1fr 250px;gap:20px;align-items:start}
@media(max-width:960px){.exam-wrap{grid-template-columns:1fr}}
.side{position:sticky;top:76px}
.navgrid{display:grid;grid-template-columns:repeat(6,1fr);gap:5px}
.navgrid a{display:block;text-align:center;font-size:12px;padding:4px 0;border:1px solid var(--line);border-radius:5px;text-decoration:none;color:var(--ink);background:#fff}
.navgrid a.done{background:var(--pri-weak);border-color:#b8c6ff}
.navgrid a.mark{outline:2px solid var(--warn)}
.navgrid a.r-ok{background:var(--ok-weak);border-color:#a7e3b9}
.navgrid a.r-bad{background:var(--bad-weak);border-color:#f5b5b5}
.navgrid a.r-part{background:var(--warn-weak);border-color:#f3d19c}
.secthead{font-weight:700;margin:22px 0 10px;padding-left:10px;border-left:4px solid var(--pri)}
.q{background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px 18px;margin-bottom:12px;scroll-margin-top:80px}
.q .qhead{display:flex;gap:8px;align-items:center;margin-bottom:6px;font-size:13px;color:var(--muted)}
.q .stem{font-size:15.5px;margin-bottom:10px;white-space:pre-wrap}
.opt{display:flex;gap:10px;align-items:flex-start;padding:8px 12px;border:1px solid var(--line);border-radius:8px;margin:6px 0;cursor:pointer;background:#fff}
.opt:hover{border-color:#b8c6ff}
.opt.sel{border-color:var(--pri);background:var(--pri-weak)}
.opt.right{border-color:var(--ok);background:var(--ok-weak)}
.opt.wrong{border-color:var(--bad);background:var(--bad-weak)}
.opt b{min-width:20px}
.opt.locked{cursor:default}
.explain{margin-top:10px;padding:12px 14px;background:#f8fafc;border-radius:8px;border-left:4px solid var(--pri);font-size:14px}
.explain .think{margin-top:8px;color:#7c3aed}
.verdict{font-weight:700;margin-top:8px}
.verdict.ok{color:var(--ok)} .verdict.bad{color:var(--bad)} .verdict.part{color:var(--warn)}
.markbtn{margin-left:auto;font-size:12px;cursor:pointer;color:var(--muted)}
.markbtn.on{color:var(--warn);font-weight:700}
.rubric{width:100%;border-collapse:collapse;font-size:13.5px;margin-top:8px}
.rubric td,.rubric th{border:1px solid var(--line);padding:6px 8px;text-align:left;vertical-align:top}
.rubric th{background:#f8fafc}
.rubric tr.hit td:first-child{color:var(--ok)}
.rubric tr.miss td:first-child{color:var(--bad)}
.md{font-size:14.5px;line-height:1.75}
.md table{border-collapse:collapse;margin:8px 0;font-size:13.5px}
.md td,.md th{border:1px solid var(--line);padding:5px 8px}
.md th{background:#f8fafc}
.md pre{background:#0f172a;color:#e2e8f0;padding:12px;border-radius:8px;overflow:auto;font-size:13px}
.md code{background:#eef1f6;padding:1px 5px;border-radius:4px;font-size:13px}
.md pre code{background:none;padding:0}
.md blockquote{margin:8px 0;padding:6px 12px;border-left:4px solid #cbd5e1;color:#475569;background:#f8fafc}
.stem-pre{white-space:pre-wrap;font-family:inherit;font-size:14.5px;background:#fbfbfd;border:1px solid var(--line);padding:14px;border-radius:8px;max-height:560px;overflow:auto}
.scorebig{font-size:48px;font-weight:800;color:var(--pri)}
.list-item{display:flex;gap:12px;align-items:center;padding:12px 0;border-bottom:1px solid var(--line)}
.list-item:last-child{border-bottom:none}
.modal{position:fixed;inset:0;background:rgba(15,23,42,.5);z-index:50;display:flex;align-items:flex-start;justify-content:center;padding:40px 16px;overflow:auto}
.modal-card{background:#fff;border-radius:12px;max-width:980px;width:100%;padding:24px 28px;position:relative}
.modal.wide{padding:12px;align-items:stretch}
.modal.wide .modal-card{max-width:1680px;height:calc(100vh - 24px);display:flex;flex-direction:column;padding:16px 20px}
.modal.wide #modal-body{flex:1;min-height:0;display:flex;flex-direction:column}
.split{flex:1;min-height:0;display:grid;grid-template-columns:1fr 1fr;gap:16px}
.split-col{overflow:auto;min-height:0;padding-right:6px}
.split-col .stem-pre{max-height:none}
.md.stem-pre{white-space:normal}
.split-head{position:sticky;top:0;z-index:2;background:#fff;display:flex;align-items:center;gap:6px;font-weight:600;padding:4px 0 8px;border-bottom:1px solid var(--line);margin-bottom:10px}
@media (max-width:900px){.split{grid-template-columns:1fr}.modal.wide .modal-card{height:auto}.split-col{overflow:visible}}
.modal-close{position:absolute;right:14px;top:10px;border:none;background:none;font-size:26px;cursor:pointer;color:var(--muted)}
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);background:#1f2937;color:#fff;padding:10px 20px;border-radius:8px;z-index:60}
.plan li{margin:4px 0}
.plan li.today{font-weight:700;color:var(--pri)}
.plan li.past{color:var(--muted);text-decoration:line-through}
.notice{background:var(--warn-weak);border:1px solid #f3d19c;color:#92400e;padding:10px 14px;border-radius:8px;font-size:14px}
.tabs{display:flex;gap:6px;margin-bottom:14px;flex-wrap:wrap}
.tabs a{padding:6px 14px;border-radius:8px;border:1px solid var(--line);background:#fff;text-decoration:none;color:var(--ink);font-size:14px}
.tabs a.on{background:var(--pri);color:#fff;border-color:var(--pri)}
.blur{filter:blur(5px);cursor:pointer;transition:.2s}
.blur:hover{filter:blur(3px)}

/* 背题模式 */
.mem-card .stem{font-size:18px}
.mem-card .opt{font-size:16px;padding:10px 14px}
.mem-flipbtn{width:100%;padding:14px;font-size:16px;margin-top:12px}
.mem-grade{display:flex;gap:10px;margin-top:14px}
.mem-grade .btn{flex:1;padding:13px;font-size:15px;justify-content:center}
/* 人话版答案 */
.plain-answer{background:#f0fdf4;border:1.5px solid #86efac;border-radius:10px;padding:10px 16px;margin:10px 0}
.plain-answer>b{color:#15803d}
.plain-answer p{margin:5px 0;font-family:var(--font-read)}
.plain-mnemonic{margin-top:8px;padding-top:6px;border-top:1px dashed #bbf7d0;color:#15803d;font-weight:700}
kbd{background:#eef1f6;border:1px solid var(--line);border-radius:4px;padding:1px 6px;font-size:12px}
.mem-hint{display:none}

/* 手机背题：碎片时间单手操作，大点击区域 + 滑动翻页 */
@media(max-width:640px){
  .mem-card .stem{font-size:16.5px}
  .mem-card .opt{padding:12px;min-height:44px}
  .mem-flipbtn{min-height:48px;padding:13px}
  .mem-grade{gap:8px}
  .mem-grade .btn{min-height:44px;padding:11px 4px;font-size:14px}
  .chip{padding:8px 14px}
  .mem-hint{display:inline}
  /* 记住/没记住固定在底部导航上方，长解析不用-scroll */
  .mem-grade{position:fixed;left:0;right:0;bottom:calc(var(--navh) + env(safe-area-inset-bottom));z-index:24;background:#fff;padding:10px 12px;box-shadow:0 -3px 12px rgba(0,0,0,.12)}
  .mem-grade+.row,#memctl{margin-bottom:76px}
}

/* ====== 阅读排版：题干、选项、解析、参考答案、答题卡、作答框用文楷；按钮、标签、表头等界面控件保持黑体；放在文件末尾以覆盖前面的字号设置 ====== */
.md,.stem,.stem-pre,.explain,.opt span,.pts,.pt-explain,.pt-quick.block,.rubric td,textarea{font-family:var(--font-read);letter-spacing:.01em;color:#262b36}
.stem,.stem-pre,.md,.opt span,textarea{font-size:16px;line-height:1.85}
.explain,.pt-explain,.pt-quick.block,.pts{font-size:15.5px;line-height:1.85}
.md table,.rubric,.pt-quick.block table{font-size:15px;line-height:1.7}
.md h1,.md h2,.md h3,.md h4{line-height:1.5;color:#1f2430}
.md p{margin:.55em 0}
.md li{margin:.25em 0}
.plan li,.kprow>span:first-child{font-family:var(--font-read);font-size:15px}
.btn,.tag,.label,.pts-head,.pt-rec,.pt-more,.split-head,th,summary,.verdict,.stat,.scorebig,.secthead,.qhead{font-family:var(--font-ui);letter-spacing:0}
code,pre,kbd,.md pre,.md code{font-family:var(--font-mono);letter-spacing:0}

/* ====== 导航与答题卡：桌面默认 ====== */
#nav a i,#nav a .s{display:none}
#nav a i{font-style:normal}
.split-tabs{display:none}
.side-bar{display:flex;align-items:center;gap:8px;margin-bottom:8px}
.side-toggle{display:none}
.side-submit-full{width:100%;margin-top:10px}

/* ====== 手机适配（≤ 640px）：底部导航、全屏弹窗、题目/答案切换、表格横向滑动、更大的点击区域 ====== */
@media (max-width:640px){
  :root{--navh:56px}
  body{font-size:15px;-webkit-text-size-adjust:100%}
  .topbar{height:46px;padding:0 12px;gap:10px}
  .brand{font-size:15px}
  .brand span{display:none}
  .topbar .timerbox{margin-left:auto}
  #nav{position:fixed;left:0;right:0;bottom:0;z-index:30;background:#162447;gap:0;overflow:visible;
       padding:4px 2px calc(4px + env(safe-area-inset-bottom));box-shadow:0 -2px 10px rgba(0,0,0,.2)}
  #nav a{flex:1;display:flex;flex-direction:column;align-items:center;gap:1px;padding:4px 0;font-size:11px;border-radius:8px;min-width:0}
  #nav a i{display:block;font-size:18px;line-height:1.2}
  #nav a .l{display:none}
  #nav a .s{display:block}
  #nav a.active{background:rgba(255,255,255,.14);color:#fff}
  main{padding:12px 10px calc(var(--navh) + 24px + env(safe-area-inset-bottom))}
  h1{font-size:19px}
  .grid{gap:10px}
  .g4{grid-template-columns:1fr 1fr}
  .g4 .card{margin-bottom:0}
  .card{padding:14px 14px;border-radius:10px}
  .q{padding:12px 12px}
  .q .qhead{flex-wrap:wrap;row-gap:4px}
  .stat{font-size:24px}
  .scorebig{font-size:38px}
  .btn{padding:9px 14px}
  .btn.sm{padding:6px 10px;min-height:32px}
  .list-item{flex-wrap:wrap;row-gap:6px}
  .kprow{grid-template-columns:88px 1fr 76px;gap:8px;font-size:13px}
  select,input,textarea{font-size:16px}
  textarea.big{min-height:360px}
  .stem-pre{max-height:none;padding:12px}
  .tabs a{padding:6px 12px}

  /* 背题卡片：减少层层内边距，让正文更宽 */
  .pts{padding:10px 10px;margin:8px -4px;border-width:1.5px}
  .pts-list,.pts.big .pts-list{padding-left:18px}
  .pt-quick{min-width:100%}
  .pt-rec{gap:6px}
  .pt-rec a,.pt-more{font-size:13px;padding:5px 10px;border:1px solid #c7d2fe;border-radius:14px;background:#fff}
  .pt-explain{padding:8px 10px}
  .pts-terms dl{grid-template-columns:1fr;gap:0 0}
  .pts-terms dd{margin:0 0 8px}
  .pt-quick.block{padding:6px 8px}

  /* 表格：列给最小宽度，整体左右滑动 */
  .md table,.rubric{display:block;overflow-x:auto;-webkit-overflow-scrolling:touch;max-width:100%}
  .md td,.md th{min-width:7.5em}
  .md td:first-child,.md th:first-child{min-width:4.5em}
  .rubric td:first-child{min-width:12em}
  .md pre{font-size:12.5px;padding:10px}

  /* 弹窗：全屏，关闭按钮固定 */
  .modal,.modal.wide{padding:0;align-items:stretch}
  .modal-card,.modal.wide .modal-card{max-width:none;min-height:100%;height:auto;border-radius:0;padding:14px 12px 40px;display:block}
  .modal.wide #modal-body{display:block}
  .modal-close{position:fixed;top:6px;right:8px;z-index:60;width:38px;height:38px;border-radius:50%;background:rgba(255,255,255,.95);box-shadow:0 1px 6px rgba(0,0,0,.2);line-height:1}
  .modal-card h2{padding-right:40px;font-size:17px}

  /* 实操：手机上题目 / 参考答案切换查看 */
  .split-tabs{display:flex;position:sticky;top:0;z-index:5;background:#fff;gap:6px;padding:6px 46px 8px 0;margin-bottom:6px;border-bottom:1px solid var(--line)}
  .split-tabs a{flex:1;text-align:center;padding:8px 0;border:1px solid var(--line);border-radius:8px;font-weight:600;text-decoration:none;color:var(--ink)}
  .split-tabs a.on{background:var(--pri);border-color:var(--pri);color:#fff}
  .split{display:block}
  .split.show-r>.split-col:first-child,.split.show-l>.split-col:last-child{display:none}
  .split-col{overflow:visible;padding-right:0}
  .split-col>.split-head:first-child{display:none}
  #case-right>.split-head{display:flex;position:static;overflow-x:auto;white-space:nowrap;flex-wrap:nowrap}

  /* 考试：答题卡变成底部浮条 */
  .exam-wrap{display:block;padding-bottom:64px}
  .side{position:fixed;left:0;right:0;top:auto;bottom:calc(var(--navh) + env(safe-area-inset-bottom));z-index:25;margin:0;border-radius:12px 12px 0 0;padding:8px 12px;box-shadow:0 -3px 12px rgba(0,0,0,.12)}
  .side-bar{margin:0}
  .side-toggle{display:inline-flex}
  .side-title,.side-submit-full,.side .navgrid{display:none}
  .side.open .navgrid{display:grid;grid-template-columns:repeat(8,1fr);max-height:42vh;overflow:auto;margin-top:8px}
  .side.open .side-title{display:block;margin-top:6px}
  .navgrid a{padding:7px 0;font-size:13px}
  .q{scroll-margin-top:60px}
}