:root{
  --bg:#f4f6fa; --card:#ffffff; --ink:#12161f; --ink2:#5a6474; --line:#e3e8f0;
  --brand:#2563eb; --brand-d:#1d4ed8; --ok:#16a34a; --ok-bg:#eafaf0;
  --bad:#dc2626; --bad-bg:#fdecec; --warn:#d97706;
  --shadow:0 1px 3px rgba(18,22,31,.06),0 8px 24px rgba(18,22,31,.06);
  --r:16px;
}
@media (prefers-color-scheme:dark){
  :root{
    --bg:#0d1017; --card:#161b25; --ink:#e8ecf3; --ink2:#909aac; --line:#252c39;
    --brand:#4f86f7; --brand-d:#3b74ea; --ok:#3ecf7a; --ok-bg:#12291c;
    --bad:#f46b6b; --bad-bg:#2c1618; --warn:#e0a44a;
    --shadow:0 1px 3px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.3);
  }
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0}
body{
  background:var(--bg); color:var(--ink);
  font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  padding:0 0 env(safe-area-inset-bottom);
}
.screen{max-width:720px;margin:0 auto;padding:16px 16px 40px}
.hidden{display:none !important}

/* ---------- 首页 ---------- */
.hero{padding:28px 4px 20px}
.hero-badge{
  display:inline-block;font-size:11px;letter-spacing:.12em;font-weight:700;
  color:var(--brand);background:color-mix(in srgb,var(--brand) 12%,transparent);
  padding:5px 10px;border-radius:99px;margin-bottom:14px;
}
.hero h1{font-size:32px;line-height:1.25;margin:0 0 10px;letter-spacing:-.02em}
.hero-sub{margin:0;color:var(--ink2);font-size:14px}
.hero-sub b{color:var(--ink)}

.stats-row{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:18px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px 10px;text-align:center}
.stat-n{font-size:22px;font-weight:750;letter-spacing:-.02em;line-height:1.2}
.stat-l{font-size:11px;color:var(--ink2);margin-top:2px}

.mode-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:18px}
.mode-card{
  display:flex;flex-direction:column;align-items:flex-start;gap:2px;
  background:var(--card);border:1px solid var(--line);border-radius:var(--r);
  padding:16px 14px;text-align:left;cursor:pointer;font-family:inherit;color:inherit;
  box-shadow:var(--shadow);transition:transform .12s,border-color .12s;
}
.mode-card:active{transform:scale(.98)}
.mode-card.primary{border-color:var(--brand);background:linear-gradient(160deg,color-mix(in srgb,var(--brand) 10%,var(--card)),var(--card))}
.mode-ico{font-size:22px;margin-bottom:6px}
.mode-name{font-size:16px;font-weight:700}
.mode-desc{font-size:12px;color:var(--ink2);line-height:1.45}

.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:16px;margin-bottom:14px;box-shadow:var(--shadow)}
.panel-title{font-size:13px;font-weight:700;color:var(--ink2);margin-bottom:12px;letter-spacing:.03em}
.chips{display:flex;flex-wrap:wrap;gap:7px}
.chip{
  font-size:12px;padding:7px 11px;border-radius:99px;cursor:pointer;
  border:1px solid var(--line);background:transparent;color:var(--ink2);font-family:inherit;
}
.chip.on{background:var(--brand);border-color:var(--brand);color:#fff;font-weight:600}
.panel-actions{display:flex;gap:8px;margin-top:12px}
.mini{font-size:12px;padding:6px 12px;border-radius:8px;border:1px solid var(--line);background:transparent;color:var(--ink2);cursor:pointer;font-family:inherit}
.opt{display:flex;align-items:center;gap:10px;padding:9px 0;font-size:14px;cursor:pointer}
.opt input{width:18px;height:18px;accent-color:var(--brand)}
.opt-row{display:flex;align-items:center;justify-content:space-between;padding:9px 0;font-size:14px}
.opt-row select{font:inherit;font-size:14px;padding:6px 10px;border-radius:8px;border:1px solid var(--line);background:var(--card);color:var(--ink)}
.danger-link{background:none;border:none;color:var(--bad);font-size:13px;padding:10px 0 0;cursor:pointer;font-family:inherit}
.foot{text-align:center;font-size:11px;color:var(--ink2);padding:8px 0 20px}

/* ---------- 答题页 ---------- */
.topbar{display:flex;align-items:center;gap:12px;padding:6px 0 16px;position:sticky;top:0;background:var(--bg);z-index:5}
.icon-btn{
  width:36px;height:36px;flex:0 0 36px;border-radius:10px;border:1px solid var(--line);
  background:var(--card);color:var(--ink);font-size:20px;line-height:1;cursor:pointer;font-family:inherit;
}
.progress-wrap{flex:1;min-width:0}
.progress-bar{height:6px;background:var(--line);border-radius:99px;overflow:hidden}
.progress-fill{height:100%;background:var(--brand);border-radius:99px;transition:width .25s}
.progress-txt{display:flex;justify-content:space-between;font-size:11px;color:var(--ink2);margin-top:5px}
.timer{font-size:14px;font-weight:700;font-variant-numeric:tabular-nums;color:var(--ink2);min-width:52px;text-align:right}
.timer.urgent{color:var(--bad)}

.qcard{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px 18px;box-shadow:var(--shadow)}
.qmeta{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px;gap:10px}
.lesson-tag{font-size:11px;color:var(--brand);background:color-mix(in srgb,var(--brand) 12%,transparent);padding:4px 9px;border-radius:99px;font-weight:600}
.qstat{font-size:11px;color:var(--ink2)}
.qtext{font-size:17px;font-weight:650;line-height:1.5;margin-bottom:6px;letter-spacing:-.01em}
.qtext.zh{font-size:15px;font-weight:600;color:var(--ink2);margin-bottom:0}
.qtext:empty{display:none}

.options{display:flex;flex-direction:column;gap:9px;margin-top:18px}
.optbtn{
  display:flex;align-items:flex-start;gap:11px;width:100%;text-align:left;
  background:transparent;border:1.5px solid var(--line);border-radius:12px;
  padding:13px 14px;cursor:pointer;font-family:inherit;color:var(--ink);
  font-size:15px;line-height:1.45;transition:border-color .12s,background .12s;
}
.optbtn:active{transform:scale(.995)}
.optkey{
  flex:0 0 24px;height:24px;border-radius:7px;background:var(--line);color:var(--ink2);
  display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700;margin-top:1px;
}
.optbody{flex:1;min-width:0}
.optzh{display:block;font-size:13px;color:var(--ink2);margin-top:2px}
.optbtn.correct{border-color:var(--ok);background:var(--ok-bg)}
.optbtn.correct .optkey{background:var(--ok);color:#fff}
.optbtn.wrong{border-color:var(--bad);background:var(--bad-bg)}
.optbtn.wrong .optkey{background:var(--bad);color:#fff}
.optbtn.locked{cursor:default}
.optbtn.dim{opacity:.5}

.explain{margin-top:18px;padding-top:16px;border-top:1px dashed var(--line)}
.explain-head{font-size:14px;font-weight:750;margin-bottom:7px}
.explain-head.ok{color:var(--ok)} .explain-head.bad{color:var(--bad)}
.explain-body{font-size:14px;line-height:1.65;color:var(--ink2)}

.bottombar{display:flex;gap:10px;margin-top:16px;align-items:center}
.primary-btn{
  flex:1;background:var(--brand);color:#fff;border:none;border-radius:12px;
  padding:14px;font-size:15px;font-weight:700;cursor:pointer;font-family:inherit;
}
.primary-btn:active{background:var(--brand-d)}
.ghost{
  background:var(--card);border:1px solid var(--line);color:var(--ink2);
  border-radius:12px;padding:14px 16px;font-size:14px;cursor:pointer;font-family:inherit;
}
.ghost.marked{color:var(--warn);border-color:var(--warn)}

.autobar{
  display:flex;align-items:center;gap:12px;margin-top:14px;background:var(--card);
  border:1px solid var(--line);border-radius:12px;padding:10px 14px;
}
.autobar input[type=range]{flex:1;accent-color:var(--brand)}
.autobar span{font-size:12px;color:var(--ink2);min-width:64px;text-align:right;font-variant-numeric:tabular-nums}

/* ---------- 结果页 ---------- */
.result-card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:28px 20px;text-align:center;margin:20px 0 14px;box-shadow:var(--shadow)}
.score-ring{
  width:132px;height:132px;border-radius:50%;margin:0 auto 16px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  background:conic-gradient(var(--brand) calc(var(--p,0)*1%), var(--line) 0);
  position:relative;
}
.score-ring::before{content:"";position:absolute;inset:11px;border-radius:50%;background:var(--card)}
.score-num{position:relative;font-size:30px;font-weight:780;letter-spacing:-.03em}
.score-lbl{position:relative;font-size:11px;color:var(--ink2)}
.verdict{font-size:19px;font-weight:750;margin-bottom:6px}
.result-meta{font-size:13px;color:var(--ink2)}

.lrow{display:flex;align-items:center;gap:10px;padding:8px 0;font-size:13px}
.lrow-name{flex:0 0 40%;color:var(--ink2);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lrow-bar{flex:1;height:7px;background:var(--line);border-radius:99px;overflow:hidden}
.lrow-fill{height:100%;border-radius:99px}
.lrow-num{flex:0 0 46px;text-align:right;font-variant-numeric:tabular-nums;color:var(--ink2);font-size:12px}

.wrong-item{padding:12px 0;border-bottom:1px solid var(--line);font-size:14px}
.wrong-item:last-child{border-bottom:none}
.wrong-q{font-weight:650;margin-bottom:5px;line-height:1.45}
.wrong-a{font-size:13px;color:var(--ink2);line-height:1.55}
.wrong-a b{color:var(--ok)}
.wrong-a i{color:var(--bad);font-style:normal}
.result-actions{display:flex;gap:10px;margin-top:18px}
.result-actions .primary-btn{flex:2}
.result-actions .ghost{flex:1;text-align:center}

@media (max-width:400px){
  .hero h1{font-size:27px}
  .mode-grid{grid-template-columns:1fr}
  .screen{padding:14px 13px 36px}
}

/* ================= 账号 / 付费相关 ================= */
.auth-screen{max-width:460px}
.acct-bar{
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;
  padding:10px 0 4px;font-size:12px;color:var(--ink2);
}
.acct-bar .acct-mail{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.acct-bar a{color:var(--brand);text-decoration:none;font-weight:600}
.acct-bar a.cta{
  background:var(--brand);color:#fff;padding:5px 11px;border-radius:99px;font-size:12px;
}
.badge-ok{background:var(--ok-bg);color:var(--ok);padding:3px 9px;border-radius:99px;font-weight:700;font-size:11px}
.badge-no{background:var(--bad-bg);color:var(--bad);padding:3px 9px;border-radius:99px;font-weight:700;font-size:11px}

.lock-banner{
  background:linear-gradient(160deg,color-mix(in srgb,var(--warn) 14%,var(--card)),var(--card));
  border:1px solid color-mix(in srgb,var(--warn) 35%,var(--line));
  border-radius:12px;padding:12px 14px;font-size:13px;line-height:1.6;margin:8px 0 4px;
}
.lock-banner a{color:var(--brand);font-weight:700;text-decoration:none;white-space:nowrap}

.tabs{display:flex;gap:6px;margin-bottom:18px;background:var(--bg);padding:4px;border-radius:11px}
.tab{
  flex:1;padding:9px;border:none;background:transparent;border-radius:8px;
  font-family:inherit;font-size:14px;color:var(--ink2);cursor:pointer;font-weight:600;
}
.tab.on{background:var(--card);color:var(--ink);box-shadow:var(--shadow)}

.field{display:block;margin-bottom:14px}
.field span{display:block;font-size:12px;color:var(--ink2);margin-bottom:6px;font-weight:600}
.field span i{font-style:normal;font-weight:400;opacity:.75}
.field input{
  width:100%;font:inherit;font-size:16px;padding:12px 14px;border-radius:11px;
  border:1.5px solid var(--line);background:var(--bg);color:var(--ink);
}
.field input:focus{outline:none;border-color:var(--brand)}

.err{background:var(--bad-bg);color:var(--bad);border-radius:10px;padding:10px 13px;font-size:13px;margin-bottom:12px;line-height:1.5}
.okmsg{background:var(--ok-bg);color:var(--ok);border-radius:10px;padding:10px 13px;font-size:13px;margin-bottom:12px;line-height:1.5}

.trial-note p{font-size:13px;line-height:1.7;margin:0 0 8px;color:var(--ink2)}
.trial-note p.muted{font-size:12px;opacity:.85;margin-bottom:0}
.trial-note b{color:var(--ink)}
.price{color:var(--brand)}

.acct-row{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:11px 0;font-size:14px;border-bottom:1px solid var(--line)}
.acct-row:last-child{border-bottom:none}
.acct-row span{color:var(--ink2)}
.acct-row b{text-align:right;font-weight:650}

.price-big{font-size:30px;font-weight:780;letter-spacing:-.02em;color:var(--brand);margin:0 0 10px}
.price-big span{font-size:15px;font-weight:600;color:var(--ink2)}
.steps{margin:12px 0;padding-left:20px;font-size:13px;line-height:1.9;color:var(--ink2)}
.paylist{display:flex;flex-direction:column;gap:8px;margin:14px 0}
.payitem{display:flex;justify-content:space-between;align-items:center;gap:10px;background:var(--bg);border-radius:10px;padding:11px 13px;font-size:13px}
.payitem b{font-weight:650}
.payitem span{color:var(--ink2);font-size:12px;text-align:right}
.muted{font-size:12px;color:var(--ink2)}

/* ================= 后台 ================= */
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.codeout{background:var(--bg);border-radius:11px;padding:12px 14px;margin-top:14px}
.codeout-head{display:flex;justify-content:space-between;align-items:center;gap:10px;font-size:12px;color:var(--ink2);margin-bottom:8px}
.codeout pre{
  margin:0;font:13px/1.9 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  letter-spacing:.06em;white-space:pre-wrap;word-break:break-all;color:var(--ink);
}
.listout{font-size:13px;color:var(--ink2);max-height:340px;overflow-y:auto}
.lrow2{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:9px 0;border-bottom:1px solid var(--line)}
.lrow2:last-child{border-bottom:none}
.lrow2 b{font-weight:650;color:var(--ink);font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px}
.lrow2 span{text-align:right;font-size:12px;flex-shrink:0}

/* ================= Zelle 收款块 ================= */
.zelle-box{
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;
  background:linear-gradient(160deg,color-mix(in srgb,var(--brand) 12%,var(--card)),var(--card));
  border:1px solid color-mix(in srgb,var(--brand) 30%,var(--line));
  border-radius:12px;padding:14px;margin:14px 0;
}
.zelle-label{font-size:11px;color:var(--ink2);width:100%;font-weight:600;letter-spacing:.03em}
.zelle-acct{
  flex:1;min-width:0;font:600 16px/1.4 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  color:var(--brand);word-break:break-all;
}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;color:var(--ink)}

/* ================= 科目切换 ================= */
.subj-switch{display:flex;gap:8px;flex-wrap:wrap;padding:6px 0 2px}
.subj{
  display:inline-flex;align-items:center;gap:6px;
  font-size:13px;font-weight:650;padding:8px 14px;border-radius:99px;
  border:1.5px solid var(--line);color:var(--ink2);text-decoration:none;
  background:var(--card);transition:border-color .12s,color .12s;
}
.subj i{font-style:normal;font-weight:500;font-size:11px;opacity:.7}
.subj.on{border-color:var(--brand);color:var(--brand);background:color-mix(in srgb,var(--brand) 10%,var(--card))}
.subj.dim{opacity:.5;cursor:default}

/* ================= 双语讲解 / 科目卡片 / 后台下拉 ================= */
.ex-zh{margin-bottom:10px}
.ex-en{
  padding-top:10px;border-top:1px solid var(--line);
  font-size:13.5px;line-height:1.7;color:var(--ink2);opacity:.95;
}
.ex-zh:only-child,.ex-en:only-child{margin:0;padding:0;border:none}

.sel{
  width:100%;font:inherit;font-size:15px;padding:11px 12px;border-radius:11px;
  border:1.5px solid var(--line);background:var(--bg);color:var(--ink);
}
.sub-en{font-size:12px;font-weight:500;color:var(--ink2)}

.subj-card .sc-head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:6px}
.subj-card .sc-head b{font-size:16px}
.subj-card .sc-price{font-size:20px;font-weight:780;color:var(--brand);letter-spacing:-.02em}
.subj-card .sc-meta{font-size:13px;color:var(--ink2);line-height:1.6;margin-bottom:14px}
.subj-card .sc-actions{display:flex;gap:9px;align-items:stretch}
.subj-card .sc-actions .primary-btn,
.subj-card .sc-actions .ghost{
  flex:1;text-align:center;text-decoration:none;display:flex;
  align-items:center;justify-content:center;padding:12px 14px;font-size:14px;
}
.subj-card .sc-actions .ghost{flex:0 0 auto;padding:12px 18px}
.subj-card.active{border-color:color-mix(in srgb,var(--ok) 40%,var(--line))}
.pricelist{display:flex;flex-direction:column;gap:8px;margin:12px 0}
.warn-txt{color:var(--warn)}
.testbadge{
  background:var(--bad-bg);color:var(--bad);border-radius:8px;
  padding:7px 11px;font-size:12px;margin-bottom:12px;font-weight:600;
}
.linkbtn{
  background:none;border:none;color:var(--brand);font:inherit;font-size:13px;
  cursor:pointer;padding:4px 8px;text-decoration:underline;text-underline-offset:3px;
}

/* ---------- 检测后补丁 ---------- */
/* 考试中的「我的选择」：中性蓝，不能用绿色——绿色暗示答对了 */
.optbtn.sel{border-color:var(--brand);background:color-mix(in srgb,var(--brand) 8%,transparent)}
.optbtn.sel .optkey{background:var(--brand);color:#fff}

/* 首页 4 格统计；「错过的」「已标记」是按钮，可以直接点进去练 */
.stats-row{grid-template-columns:repeat(4,1fr)}
button.stat.click{cursor:pointer;font:inherit;color:inherit}
button.stat.click:hover{border-color:var(--brand)}
button.stat.click .stat-l{color:var(--brand)}

/* 顶部进度条可点开答题卡 */
.progress-wrap{cursor:pointer}
.sheet-hint{color:var(--brand);font-size:11px;margin-left:8px}

/* 答题卡浮层 */
.sheet{position:fixed;inset:0;z-index:60;background:rgba(10,14,22,.5);
  display:flex;align-items:flex-end;justify-content:center}
.sheet-box{background:var(--card);width:100%;max-width:720px;
  border-radius:18px 18px 0 0;padding:16px 16px calc(16px + env(safe-area-inset-bottom));
  max-height:72vh;overflow:auto;box-shadow:var(--shadow)}
.sheet-head{display:flex;justify-content:space-between;align-items:center;
  margin-bottom:12px;font-weight:650}
.sheet-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(42px,1fr));
  gap:8px;margin-bottom:12px}
.sheet-cell{aspect-ratio:1;border:1.5px solid var(--line);border-radius:10px;
  background:none;font:600 13px/1 inherit;font-family:inherit;color:var(--ink2);
  position:relative;cursor:pointer;padding:0}
.sheet-cell.cur{outline:2px solid var(--brand);outline-offset:1px}
.sheet-cell.done{background:var(--brand);border-color:var(--brand);color:#fff}
.sheet-cell.right{background:var(--ok-bg);border-color:var(--ok);color:var(--ok)}
.sheet-cell.wrong2{background:var(--bad-bg);border-color:var(--bad);color:var(--bad)}
.sheet-cell.marked::after{content:'★';position:absolute;top:-7px;right:-3px;
  font-size:11px;color:var(--warn)}
.sheet-legend{font-size:12px;color:var(--ink2);margin-bottom:12px}
.sheet-submit{width:100%}