:root{
  --bg:#f5f7fb; --card:#ffffff; --ink:#1f2937; --muted:#6b7280; --line:#e6e9f0;
  --accent:#2f6fed; --accent-soft:#eaf1ff; --ok:#16a34a; --ok-soft:#e8f7ee;
  --bad:#dc2626; --bad-soft:#fdeceb; --warn:#b45309; --shadow:0 1px 2px rgba(17,24,39,.04),0 8px 24px rgba(17,24,39,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:var(--bg); color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:16px; line-height:1.55; -webkit-text-size-adjust:100%;
}
#app{max-width:720px;margin:0 auto;padding:18px 16px 48px}
.top{display:flex;align-items:baseline;justify-content:space-between;gap:10px;margin-bottom:14px}
.brand{font-size:18px;font-weight:700;letter-spacing:.2px}
.brand .fox{margin-right:6px}
.sub{font-size:12.5px;color:var(--muted)}
.hint{font-size:13px;color:var(--muted);margin:0 0 12px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow)}
.strip{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 16px;margin-bottom:14px}
.strip .big{font-size:22px;font-weight:750;letter-spacing:.3px}
.strip .big span{font-size:13px;font-weight:500;color:var(--muted);margin-left:6px}
.strip .side{font-size:12.5px;color:var(--muted);text-align:right}
.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
@media(min-width:560px){.grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
.lcard{position:relative;padding:14px;text-align:left;border-radius:14px;border:1px solid var(--line);background:#fff;cursor:pointer;
  transition:transform .08s ease,border-color .15s ease,box-shadow .15s ease;font:inherit;color:inherit;width:100%}
.lcard:hover{border-color:#c9d6f5;box-shadow:var(--shadow)}
.lcard:active{transform:scale(.985)}
.lcard .no{font-size:12px;font-weight:700;color:var(--accent);letter-spacing:.6px}
.lcard .nm{font-size:17px;font-weight:700;margin:3px 0 6px}
.lcard .meta{font-size:12px;color:var(--muted)}
.lcard.locked{background:#f2f4f8;border-style:dashed;color:#9aa3b2;cursor:not-allowed}
.lcard.locked .no{color:#9aa3b2}
.badge{position:absolute;top:10px;right:10px;font-size:11px;font-weight:600;padding:2px 7px;border-radius:999px;background:var(--accent-soft);color:var(--accent)}
.badge.done{background:var(--ok-soft);color:var(--ok)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:0;border-radius:12px;padding:13px 18px;
  font:inherit;font-weight:650;cursor:pointer;background:var(--accent);color:#fff;transition:filter .15s ease}
.btn:hover{filter:brightness(1.06)}
.btn.ghost{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn.block{width:100%}
.btnrow{display:flex;gap:10px;margin-top:14px;flex-wrap:wrap}
.bar{height:6px;border-radius:999px;background:#e9edf5;overflow:hidden}
.bar i{display:block;height:100%;background:var(--accent);border-radius:999px;transition:width .2s ease}
.qhead{display:flex;align-items:center;justify-content:space-between;font-size:12.5px;color:var(--muted);margin-bottom:8px}
.qcard{padding:22px 18px;text-align:center;margin:10px 0 14px}
.qtag{display:inline-block;font-size:11.5px;font-weight:700;letter-spacing:.5px;padding:3px 9px;border-radius:999px;background:var(--accent-soft);color:var(--accent);margin-bottom:12px}
.qtag.ec{background:#f3ecff;color:#7c3aed}
.qprompt{font-size:26px;font-weight:750;line-height:1.35;word-break:break-word}
.qprompt.cn{font-size:18px;font-weight:600;line-height:1.6}
.opts{display:grid;gap:9px}
.opt{width:100%;text-align:left;padding:14px 16px;border-radius:12px;border:1.5px solid var(--line);background:#fff;font:inherit;color:inherit;cursor:pointer;transition:border-color .12s ease,background .12s ease}
.opt:hover:not(.dis){border-color:#bcd0f7;background:#fbfcff}
.opt .en{font-size:17px;font-weight:650}
.opt .cn{font-size:15px;line-height:1.5}
.opt.ok{border-color:var(--ok);background:var(--ok-soft)}
.opt.bad{border-color:var(--bad);background:var(--bad-soft)}
.opt.dis{cursor:default}
.optrow{display:flex;align-items:center;justify-content:space-between;gap:10px}
.mark{font-size:15px;font-weight:700}
.foot{display:flex;justify-content:space-between;align-items:center;margin-top:16px;gap:10px}
.wl{list-style:none;padding:0;margin:0}
.wl li{display:flex;gap:10px;padding:9px 2px;border-bottom:1px solid var(--line)}
.wl li:last-child{border-bottom:0}
.wl .w{font-weight:650;min-width:96px;word-break:break-word}
.wl .m{color:var(--muted);font-size:14px}
.sec-title{font-size:14px;font-weight:700;margin:20px 0 8px}
.res-score{text-align:center;padding:22px 16px 18px}
.res-score .pct{font-size:46px;font-weight:800;letter-spacing:-1px;line-height:1.1}
.res-score .frac{font-size:14px;color:var(--muted);margin-top:6px}
.stats{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-top:14px}
.stat{padding:12px 14px;border-radius:12px;background:#fff;border:1px solid var(--line)}
.stat .k{font-size:12px;color:var(--muted)}
.stat .v{font-size:18px;font-weight:750;margin-top:2px}
.up{color:var(--ok)} .down{color:var(--bad)}
.empty{padding:16px;border-radius:12px;background:#fff;border:1px dashed var(--line);color:var(--muted);font-size:13.5px;text-align:center}
.chart{background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px 12px 8px;box-shadow:var(--shadow)}
.chart svg{width:100%;height:auto;display:block}
.chart .lbl{font-size:11px;fill:#6b7280}
.chart .val{font-size:11px;font-weight:700;fill:#1f2937}
.reset{margin-top:26px;text-align:center}
.reset button{background:none;border:0;color:#9aa3b2;font-size:12px;cursor:pointer;text-decoration:underline}
.note{font-size:12.5px;color:var(--muted);margin-top:10px;text-align:center}
details.review{margin-top:16px}
details.review summary{cursor:pointer;font-size:14px;font-weight:650;padding:10px 0}
.wronglist{display:grid;gap:8px}
.wronglist .row{padding:10px 12px;border-radius:10px;background:#fff;border:1px solid var(--line);font-size:14px}
.wronglist .row b{font-weight:700}
.wronglist .row .tag{font-size:11px;color:var(--muted);margin-right:6px}