:root{--p:#1677ff;--ok:#16a34a;--bad:#dc2626;--part:#d97706;--bg:#f5f6f8;--card:#fff;--txt:#1f2329;--muted:#6b7280;--line:#e5e7eb}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0;background:var(--bg);color:var(--txt);font:16px/1.55 -apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue","Microsoft YaHei",sans-serif}
body{padding-bottom:env(safe-area-inset-bottom)}
.view{display:none;max-width:720px;margin:0 auto;padding:16px 14px 40px}
.view.active{display:block}
h1{font-size:22px;margin:8px 0 4px}
h2{font-size:18px;margin:18px 0 8px}
.sub{color:var(--muted);font-size:14px;margin:0 0 14px}
.card{background:var(--card);border-radius:12px;padding:14px;margin:10px 0;box-shadow:0 1px 2px rgba(0,0,0,.04)}
.btn{display:inline-block;width:100%;padding:13px 16px;border:0;border-radius:10px;background:var(--p);color:#fff;font-size:17px;font-weight:600;text-align:center;cursor:pointer}
.btn.secondary{background:#fff;color:var(--p);border:1px solid var(--p)}
.btn.wechat{background:#07c160}
.btn.small{width:auto;padding:8px 14px;font-size:14px;font-weight:500}
.btn:disabled{opacity:.5}
.btn+.btn{margin-top:10px}
input[type=text],textarea{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:10px;font-size:16px;background:#fff;outline:none}
input[type=text]:focus,textarea:focus{border-color:var(--p)}
textarea{min-height:120px;resize:vertical;line-height:1.5}
label.f{display:block;font-size:14px;color:var(--muted);margin:10px 0 6px}
.err{color:var(--bad);font-size:14px;min-height:20px;margin-top:8px}
.rules li{margin:6px 0}
.topbar{position:sticky;top:0;z-index:5;background:#fff;border-bottom:1px solid var(--line);margin:-16px -14px 12px;padding:10px 14px;display:flex;align-items:center;justify-content:space-between;gap:10px}
.timer{font-variant-numeric:tabular-nums;font-weight:700;font-size:20px}
.timer.warn{color:var(--bad)}
.progress{font-size:13px;color:var(--muted)}
.chips{display:flex;gap:8px;overflow-x:auto;padding-bottom:6px;margin-bottom:6px}
.chip{flex:0 0 auto;padding:6px 12px;border-radius:999px;background:#fff;border:1px solid var(--line);font-size:13px;color:var(--muted);white-space:nowrap}
.mod-title{font-size:15px;font-weight:700;margin:18px 0 6px;color:#374151}
.q{background:var(--card);border-radius:12px;padding:14px;margin:10px 0}
.q .head{display:flex;align-items:center;gap:8px;margin-bottom:8px;font-size:13px;color:var(--muted)}
.tag{display:inline-block;padding:1px 8px;border-radius:6px;font-size:12px;background:#eef2ff;color:#3730a3}
.tag.multi{background:#fef3c7;color:#92400e}.tag.calc{background:#dcfce7;color:#166534}.tag.scenario{background:#fee2e2;color:#991b1b}
.q .stem{font-size:16px;line-height:1.6;white-space:pre-wrap}
.opts{margin-top:10px}
.opt{display:flex;align-items:flex-start;gap:10px;padding:11px 12px;border:1px solid var(--line);border-radius:10px;margin:8px 0;cursor:pointer;background:#fff}
.opt input{margin:4px 0 0;width:18px;height:18px;flex:0 0 18px}
.opt.sel{border-color:var(--p);background:#eff6ff}
.opt.correct{border-color:var(--ok);background:#f0fdf4}
.opt.wrong{border-color:var(--bad);background:#fef2f2}
.opt .k{font-weight:700;margin-right:2px}
.counter{font-size:12px;color:var(--muted);text-align:right;margin-top:4px}
.hint{font-size:13px;color:var(--muted);margin-top:6px}
.bottom{margin-top:20px}
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.45);display:none;align-items:center;justify-content:center;z-index:20;padding:20px}
.modal-bg.show{display:flex}
.modal{background:#fff;border-radius:14px;padding:18px;width:100%;max-width:420px}
.modal h3{margin:0 0 10px;font-size:18px}
.modal .row{display:flex;gap:10px;margin-top:14px}
.modal .row .btn{margin:0}
.score-card{text-align:center;padding:22px 14px}
.score-num{font-size:56px;font-weight:800;color:var(--p);line-height:1}
.score-num small{font-size:18px;color:var(--muted);font-weight:500}
.score-meta{color:var(--muted);font-size:14px;margin-top:8px}
.badge{display:inline-block;padding:2px 10px;border-radius:999px;font-size:12px;font-weight:600}
.badge.correct{background:#dcfce7;color:#166534}.badge.wrong{background:#fee2e2;color:#991b1b}.badge.partial{background:#fef3c7;color:#92400e}.badge.pending{background:#e0e7ff;color:#3730a3}.badge.blank{background:#f3f4f6;color:#4b5563}.badge.ungraded{background:#f3f4f6;color:#4b5563}
table.mods{width:100%;border-collapse:collapse;font-size:14px}
table.mods td,table.mods th{padding:8px 6px;border-bottom:1px solid var(--line);text-align:left}
table.mods td:last-child,table.mods th:last-child{text-align:right;white-space:nowrap}
.ai-box{background:#f8fafc;border-left:3px solid var(--p);padding:10px 12px;border-radius:8px;margin-top:10px;font-size:14px;white-space:pre-wrap}
.ai-box.wait{color:var(--muted)}
.ref{margin-top:10px;font-size:14px;color:#374151;background:#f9fafb;border-radius:8px;padding:10px 12px;white-space:pre-wrap}
.ref b{color:#111827}
.your{margin-top:10px;font-size:14px;white-space:pre-wrap}
.filter{display:flex;gap:8px;margin:10px 0}
.filter .chip.on{background:var(--p);color:#fff;border-color:var(--p)}
.spinner{display:inline-block;width:14px;height:14px;border:2px solid #cbd5e1;border-top-color:var(--p);border-radius:50%;animation:sp .8s linear infinite;vertical-align:-2px;margin-right:6px}
@keyframes sp{to{transform:rotate(360deg)}}
.toast{position:fixed;left:50%;bottom:40px;transform:translateX(-50%);background:rgba(17,24,39,.9);color:#fff;padding:10px 16px;border-radius:10px;font-size:14px;z-index:30;display:none}
.toast.show{display:block}
.muted{color:var(--muted)}