:root{--bg: #f5f7fb;--card: #fff;--text: #172033;--muted: #6b7280;--line: #e6eaf0;--accent: #2563eb;--radius: 18px}*{box-sizing:border-box}body{margin:0;min-width:320px;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif;background:var(--bg);color:var(--text)}button{font:inherit}button:focus-visible{outline:3px solid var(--accent);outline-offset:3px}.shell{max-width:980px;margin:0 auto;padding:28px 18px 56px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:22px}.brand h1{margin:0 0 6px;font-size:24px}.brand p{margin:0;color:var(--muted);font-size:14px}.pill{padding:8px 12px;border-radius:999px;background:#eef4ff;color:#174ea6;font-size:13px;font-weight:700;white-space:nowrap}.grid{display:grid;grid-template-columns:1.35fr .65fr;gap:18px}.card{padding:20px;border:1px solid var(--line);border-radius:var(--radius);background:var(--card);box-shadow:0 8px 30px #1018280d}.hero{padding:26px}h2{margin:0 0 12px;font-size:20px}h3{margin:0 0 10px;font-size:16px}p{line-height:1.7}.muted{color:var(--muted)}.mini{color:var(--muted);font-size:12px}.big-rating{margin:8px 0;font-size:52px;font-weight:800;letter-spacing:-2px}.btn{border:0;border-radius:12px;padding:12px 16px;cursor:pointer;font-weight:700}.btn.primary{background:var(--accent);color:#fff}.btn.secondary{background:#eef2f7;color:#24324a}.btn.ghost{border:1px solid var(--line);background:#fff;color:#344054}.btn:disabled{cursor:not-allowed;opacity:.45}.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}.centered{justify-content:center}.notice{margin-top:18px;padding:12px 14px;border:1px solid #fde68a;border-radius:12px;background:#fffbeb;color:#7c4a03;font-size:13px;line-height:1.6}.dashboard-detail{margin-top:18px}.skill{margin:15px 0}.skill-row{display:flex;justify-content:space-between;gap:8px;margin-bottom:6px;font-size:14px}.skill-name{font-weight:700}.bar{height:9px;overflow:hidden;border-radius:999px;background:#edf0f5}.bar i{display:block;height:100%;border-radius:999px;background:var(--accent);transition:width .2s ease}.tag{display:inline-block;margin:3px 4px 3px 0;padding:5px 8px;border-radius:999px;background:#f2f4f7;font-size:12px}.grade-picker{display:grid;grid-template-columns:1fr 1.2fr;gap:18px;align-items:center;margin-top:20px;padding:14px;border:1px solid #dbe5f5;border-radius:14px;background:#f8fbff}.grade-picker h2{margin-bottom:6px}.grade-picker p{margin:0}.grade-options{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}.grade-option{min-height:40px;border:1px solid var(--line);border-radius:10px;background:#fff;color:#344054;cursor:pointer;font-size:13px;font-weight:700}.grade-option:hover{border-color:#9bbcff;background:#f7faff}.grade-option.active{border-color:var(--accent);background:#eff6ff;color:#174ea6}.tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}.tab{border:1px solid var(--line);border-radius:999px;padding:9px 14px;cursor:pointer;background:#fff;color:#344054;font-weight:700}.tab.active{border-color:#9bbcff;background:#eef4ff;color:#174ea6}.premium-card{padding:18px;border:1px solid #d8c7ff;border-radius:16px;background:linear-gradient(180deg,#fbf9ff,#f7f4ff)}.premium-badge{display:inline-block;margin-bottom:10px;padding:5px 9px;border-radius:999px;background:#6d4aff;color:#fff;font-size:12px;font-weight:800}.locked{position:relative;overflow:hidden;padding:16px;border:1px dashed #cfd6e4;border-radius:14px;background:#fafbfc}.lock-overlay{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;padding:18px;background:#ffffffd6;text-align:center}.lock-overlay strong{display:block;margin-bottom:6px}.compare-row{display:flex;justify-content:space-between;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}.compare-row:last-child{border-bottom:none}.footer-note{margin-top:20px;color:var(--muted);font-size:12px;line-height:1.6}.q-meta{display:flex;justify-content:space-between;gap:12px;margin-bottom:12px;color:var(--muted);font-size:13px}.progress{height:8px;overflow:hidden;margin:12px 0 22px;border-radius:999px;background:#edf0f5}.progress i{display:block;height:100%;background:var(--accent)}.question{margin:18px 0 20px;font-size:22px;font-weight:750;line-height:1.55}.choices{display:grid;gap:10px}.choice{width:100%;padding:13px 14px;border:1px solid var(--line);border-radius:13px;cursor:pointer;background:#fff;text-align:left}.choice:hover:not(:disabled){border-color:#b8c5db}.choice.selected{border-color:var(--accent);background:#eff6ff}.choice.correct{border-color:#86c998;background:#effaf2}.choice.wrong{border-color:#f4a9a3;background:#fff1f0}.confidence-wrap{margin-top:14px}.confidence{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px}.confidence button{padding:8px 12px;border:1px solid var(--line);border-radius:999px;cursor:pointer;background:#f5f7fa}.confidence button.selected{border-color:#8eb3ff;background:#eef4ff;color:#174ea6;font-weight:700}.hint{margin-top:12px;padding:10px 12px;border-radius:10px;background:#f7f9fc;color:#44506a;font-size:14px}.feedback{display:none;margin-top:18px;padding:16px;border-radius:14px}.feedback.show{display:block}.feedback.good{border:1px solid #b7e2c2;background:#effaf2}.feedback.bad{border:1px solid #ffd0c9;background:#fff4f2}.feedback h3{margin-bottom:6px}.explain{line-height:1.75}.result-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.metric{padding:14px;border:1px solid var(--line);border-radius:14px;background:#f8fafc}.metric b{font-size:24px}.metric .compact-value,.compact-value{font-size:18px}.report-section{padding:16px 0;border-bottom:1px solid var(--line)}.report-section:last-of-type{border-bottom:0}.report-locked{min-height:170px}.status-chip{display:inline-block;padding:5px 9px;border-radius:999px;background:#fff7ed;color:#9a3412;font-size:12px;font-weight:700}.paywall-price{margin:6px 0;font-size:30px;font-weight:850;letter-spacing:-1px}.review-heading{margin-top:20px}.wrong-answer{padding:12px 0;border-bottom:1px solid var(--line)}.table-wrap{overflow:auto}.history{width:100%;border-collapse:collapse;font-size:13px}.history th,.history td{padding:10px 8px;border-bottom:1px solid var(--line);text-align:left}.history th{color:var(--muted);font-weight:600}@media(max-width:780px){.grid,.result-grid,.grade-picker{grid-template-columns:1fr}.grade-options{grid-template-columns:repeat(3,minmax(0,1fr))}.big-rating{font-size:44px}.question{font-size:19px}.topbar{align-items:flex-start}}