:root{
  --green:#2EA121;--green-2:#eaf6e8;--green-3:#cfe9ca;
  --bg:#f4f7f4;--card:#fff;--text:#1d2a21;--muted:#728078;
  --line:#e3e9e4;--red:#d84a4a;--red-bg:#fff0f0;--amber:#b97812;--amber-bg:#fff7e5;
  --shadow:0 10px 30px rgba(30,50,34,.08);--radius:18px
}
*{box-sizing:border-box}
html,body{margin:0;min-height:100%;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;color:var(--text);background:var(--bg)}
button{font:inherit}
.app-shell{max-width:1280px;margin:auto;padding:18px}
.topbar{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:18px}
.eyebrow{font-size:12px;font-weight:800;color:var(--green);letter-spacing:.12em;text-transform:uppercase}
h1{margin:4px 0 0;font-size:26px}.top-actions{display:flex;gap:10px;align-items:center}
.ghost-btn,.btn{border:1px solid var(--line);background:#fff;border-radius:11px;padding:10px 14px;cursor:pointer;font-weight:700}
.btn.primary{background:var(--green);color:#fff;border-color:var(--green)}.btn.danger{color:var(--red)}
.sync-badge{font-size:12px;padding:8px 10px;border-radius:999px;background:var(--green-2);color:var(--green);font-weight:800}
.layout{display:grid;grid-template-columns:230px 1fr;gap:18px}
.sidebar{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:10px;box-shadow:var(--shadow);height:max-content;position:sticky;top:18px}
.nav{display:block;width:100%;border:0;background:transparent;text-align:left;padding:12px 14px;border-radius:12px;cursor:pointer;margin:3px 0}
.nav:hover,.nav.active{background:var(--green-2);color:var(--green);font-weight:800}
.main{min-width:0}.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:20px;margin-bottom:16px}
.hero{display:flex;justify-content:space-between;gap:20px;align-items:center}.hero h2{margin:0 0 8px;font-size:28px}.hero p{margin:0;color:var(--muted);line-height:1.8}
.hero-emoji{font-size:66px}.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}
.stat{padding:16px;border:1px solid var(--line);border-radius:14px}.stat .label{font-size:13px;color:var(--muted)}.stat .value{font-size:28px;font-weight:900;margin-top:6px}
.row{display:flex;justify-content:space-between;gap:12px;align-items:center;flex-wrap:wrap}.muted{color:var(--muted)}
.progress{height:10px;background:#edf1ee;border-radius:999px;overflow:hidden}.progress>div{height:100%;background:var(--green)}
.chips{display:flex;gap:8px;flex-wrap:wrap}.chip{font-size:12px;padding:6px 9px;border-radius:999px;background:#f0f3f1}.chip.green{background:var(--green-2);color:var(--green)}.chip.hot{background:var(--amber-bg);color:var(--amber)}
.q-title{font-size:21px;line-height:1.7;margin:18px 0}.option{display:flex;gap:10px;border:1px solid var(--line);border-radius:13px;padding:13px 14px;margin:10px 0;cursor:pointer}
.option:hover{border-color:#bcd7b7;background:#fcfffb}.option.selected{border-color:var(--green);background:var(--green-2)}.option.correct{border-color:#66af5b;background:#edf9ea}.option.wrong{border-color:var(--red);background:var(--red-bg)}
.letter{font-weight:900;min-width:24px}.result{margin-top:18px;padding:16px;border-radius:14px;line-height:1.75}.result.ok{background:#edf9ea;border:1px solid #c7e8c2}.result.no{background:var(--red-bg);border:1px solid #f0c7c7}
.explain{margin-top:12px;padding-top:12px;border-top:1px dashed #cdd6cf}
.table-wrap{overflow:auto}.table{width:100%;border-collapse:collapse}.table th,.table td{padding:10px;border-bottom:1px solid var(--line);text-align:left;font-size:14px}
.empty{text-align:center;padding:38px;color:var(--muted)}.empty .big{font-size:54px}
.update-box{background:#f8fbf8;border:1px solid var(--green-3);border-radius:14px;padding:14px}
.toast{position:fixed;right:20px;bottom:20px;max-width:360px;background:#182019;color:#fff;padding:12px 16px;border-radius:12px;box-shadow:var(--shadow);opacity:0;transform:translateY(10px);pointer-events:none;transition:.2s}
.toast.show{opacity:1;transform:none}.toast.error{background:#7e2222}
@media(max-width:820px){.layout{grid-template-columns:1fr}.sidebar{position:static;display:flex;gap:6px;overflow:auto}.nav{width:auto;white-space:nowrap}.stats-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:520px){.app-shell{padding:10px}.topbar{align-items:flex-start}.top-actions{flex-direction:column;align-items:flex-end}.hero{display:block}.hero-emoji{display:none}.card{padding:15px}}