:root{--bg:#f4f7fb;--card:#fff;--text:#111827;--muted:#667085;--line:#e5e7eb;--brand:#0f766e;--brand2:#115e59;--ok:#16a34a;--bad:#dc2626;--warn:#d97706;--soft:#ecfdf5;--badsoft:#fef2f2;--shadow:0 14px 36px rgba(15,23,42,.08);--radius:18px}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",Arial,sans-serif;line-height:1.6}.topbar{position:sticky;top:0;z-index:10;background:rgba(255,255,255,.94);backdrop-filter:blur(10px);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:12px max(16px,env(safe-area-inset-left));gap:12px}.brand{display:flex;align-items:center;gap:12px}.logo{width:42px;height:42px;border-radius:14px;background:linear-gradient(135deg,var(--brand),#14b8a6);color:#fff;display:grid;place-items:center;font-weight:900}.brand h1{font-size:18px;margin:0}.brand p{font-size:12px;color:var(--muted);margin:2px 0 0}.top-actions{display:flex;align-items:center;gap:8px}.user-email{font-size:13px;color:var(--muted);max-width:180px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.sync-status{font-size:12px;color:var(--muted);background:#f8fafc;border:1px solid var(--line);border-radius:999px;padding:3px 8px;white-space:nowrap}.sync-status.ok{color:var(--ok);background:#f0fdf4;border-color:#bbf7d0}.sync-status.saving{color:var(--warn);background:#fffbeb;border-color:#fde68a}.sync-status.bad{color:var(--bad);background:#fef2f2;border-color:#fecaca}main{max-width:1200px;margin:0 auto;padding:18px}.notice,.auth-card,.panel{background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:var(--radius)}.notice{padding:14px 16px;margin-bottom:16px}.auth-card{max-width:520px;margin:34px auto;padding:22px}.tabs{display:grid;grid-template-columns:1fr 1fr;background:#f1f5f9;border-radius:14px;padding:4px;margin-bottom:18px}.tab{border:0;background:transparent;border-radius:12px;padding:10px;font-weight:800;color:var(--muted)}.tab.active{background:#fff;color:var(--brand);box-shadow:0 4px 12px rgba(15,23,42,.06)}.auth-form{display:grid;gap:14px}.auth-form h2{margin:0;font-size:18px}label{display:grid;gap:6px;font-weight:800;font-size:13px;color:#344054}input,select{width:100%;border:1px solid var(--line);border-radius:12px;padding:11px 12px;font-size:15px;background:#fff;color:var(--text)}button{border:0;border-radius:12px;padding:11px 14px;font-weight:900;font-size:14px;cursor:pointer}button:disabled{opacity:.5;cursor:not-allowed}.primary{background:var(--brand);color:#fff}.primary:hover{background:var(--brand2)}.ghost{background:#f8fafc;color:#334155;border:1px solid var(--line)}.danger{background:#fff1f2;color:#be123c;border:1px solid #fecdd3}.small{padding:7px 10px;font-size:12px}.full{width:100%}.hint,.message,.muted{font-size:13px;color:var(--muted)}.message{min-height:20px}.message.error{color:var(--bad)}.message.ok{color:var(--ok)}.layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:18px}.panel{padding:18px}.toolbar{display:grid;grid-template-columns:1fr 1fr 140px auto;gap:12px;align-items:end;margin-bottom:16px}.q-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:10px}.tag{display:inline-flex;align-items:center;border-radius:999px;padding:3px 10px;background:#e6fffa;color:var(--brand);font-weight:900;font-size:12px}.question-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px}.case-stem{background:#f8fafc;border-left:4px solid var(--brand);padding:12px 14px;border-radius:12px;margin-bottom:14px;white-space:pre-wrap}.question-card h2{font-size:20px;margin:0 0 16px;line-height:1.55}.options{display:grid;gap:10px}.option{display:grid;grid-template-columns:34px minmax(0,1fr);gap:10px;align-items:start;text-align:left;width:100%;background:#fff;border:1.5px solid var(--line);border-radius:14px;padding:12px}.option:hover{border-color:#99f6e4;background:#f0fdfa}.option.selected{border-color:var(--brand);background:#ecfdf5}.option.correct{border-color:var(--ok);background:var(--soft)}.option.wrong{border-color:var(--bad);background:var(--badsoft)}.letter{width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:#f1f5f9;font-weight:900}.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}.result{margin-top:16px;border-radius:14px;padding:14px;border:1px solid var(--line);background:#f8fafc}.result.ok{background:#f0fdf4;border-color:#bbf7d0}.result.bad{background:#fef2f2;border-color:#fecaca}.result h3{margin:0 0 8px}.stats{display:grid;grid-template-columns:1fr 1fr;gap:10px}.stats div{background:#f8fafc;border:1px solid var(--line);border-radius:14px;padding:12px;text-align:center}.stats b{display:block;font-size:22px}.stats span{font-size:12px;color:var(--muted)}.side-actions{display:grid;gap:8px;margin:14px 0}.side-panel h3{margin:14px 0 10px}.answer-card{display:grid;grid-template-columns:repeat(6,1fr);gap:8px;max-height:62vh;overflow:auto;padding-right:3px}.answer-card button{padding:8px 0;border-radius:10px;border:1px solid var(--line);background:#fff;color:#334155}.answer-card button.active{outline:2px solid var(--brand)}.answer-card button.done{background:#eff6ff;border-color:#bfdbfe}.answer-card button.ok{background:#ecfdf5;border-color:#86efac;color:#166534}.answer-card button.bad{background:#fef2f2;border-color:#fca5a5;color:#991b1b}.answer-card button.starred::after{content:'★';font-size:9px;margin-left:2px;color:#d97706}@media (max-width:900px){main{padding:12px}.topbar{align-items:flex-start}.layout{grid-template-columns:1fr}.toolbar{grid-template-columns:1fr 1fr}.toolbar button{grid-column:1/-1}.side-panel{order:2}.answer-card{max-height:none;grid-template-columns:repeat(8,1fr)}.question-card h2{font-size:18px}.top-actions{flex-direction:column;align-items:flex-end;gap:4px}}@media (max-width:560px){.brand h1{font-size:16px}.logo{width:38px;height:38px}.auth-card{margin:16px 0;padding:16px}.toolbar{grid-template-columns:1fr}.panel{padding:14px}.question-card{padding:14px}.option{grid-template-columns:30px 1fr;padding:11px}.actions button{flex:1 1 42%}.answer-card{grid-template-columns:repeat(6,1fr)}.user-email{display:none}}