:root{color-scheme:light;--bg:#f5f7f8;--panel:#ffffff;--ink:#172126;--muted:#65727b;--line:#dbe2e6;--brand:#126c64;--brand-dark:#0d514b;--accent:#c85f2f;--ok:#1f7a4d;--bad:#bd3b3b;--soft:#eef4f3}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:Arial,Microsoft YaHei,sans-serif}button{font:inherit}.shell{min-height:100vh;padding:28px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;margin:0 auto 20px;max-width:1160px}h1,h2,p{margin:0}h1{font-size:32px;line-height:1.2}.topbar p{color:var(--muted);margin-top:8px}.iconButton{align-items:center;background:var(--panel);border:1px solid var(--line);border-radius:8px;color:var(--ink);cursor:pointer;display:inline-flex;height:44px;justify-content:center;width:44px}.workspace{display:grid;grid-gap:14px;gap:14px;margin:0 auto;max-width:1160px}.statsGrid{display:grid;grid-gap:10px;gap:10px;grid-template-columns:1fr;margin-bottom:16px}.questionPanel,.sidePanel,.stat{background:var(--panel);border:1px solid var(--line);border-radius:8px}.stat{padding:12px}.stat span,.typeRow span{color:var(--muted);font-size:14px}.stat strong{display:block;font-size:24px;line-height:1.15;margin-top:6px}.workspace{align-items:start;grid-template-columns:260px minmax(0,1fr)}.questionPanel,.sidePanel{padding:18px}.mobileProgress{display:none}.panelTitle{font-weight:700;gap:8px;margin-bottom:12px}.panelTitle,.typeRow{align-items:center;display:flex}.typeRow{justify-content:space-between;padding:12px 0}.coverage,.typeRow{border-top:1px solid var(--line)}.coverage{padding-top:14px}.coverage p{color:var(--muted);font-size:13px;margin-top:8px}.coverageBar{background:#e9eef0;border-radius:999px;height:10px;overflow:hidden}.coverageBar span{background:var(--brand);display:block;height:100%}.questionMeta{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}.questionMeta span{background:var(--soft);border:1px solid #d4e2df;border-radius:999px;color:var(--brand-dark);font-size:13px;padding:5px 10px}h2{font-size:24px;line-height:1.45;margin-bottom:18px}.options{display:grid;grid-gap:10px;gap:10px}.option{align-items:flex-start;background:#fff;border:1px solid var(--line);border-radius:8px;color:var(--ink);cursor:pointer;display:grid;grid-gap:12px;gap:12px;grid-template-columns:34px minmax(0,1fr);min-height:58px;padding:12px;text-align:left}.option.picked,.option:hover{border-color:var(--brand);background:#f3faf8}.option.right{border-color:var(--ok);background:#edf8f1}.option.wrong{border-color:var(--bad);background:#fff0f0}.optionLabel{align-items:center;background:#e8eef0;border-radius:8px;display:inline-flex;font-weight:700;height:34px;justify-content:center;width:34px}.result{align-items:flex-start;border-radius:8px;display:flex;gap:10px;margin-top:16px;padding:12px}.result p{margin-top:4px}.result.correct{background:#edf8f1;color:var(--ok)}.result.incorrect{background:#fff0f0;color:var(--bad)}.actions{display:flex;gap:10px;margin-top:18px}.primary,.secondary{align-items:center;border-radius:8px;cursor:pointer;display:inline-flex;gap:6px;justify-content:center;min-height:44px;padding:0 16px}.primary{background:var(--brand);border:1px solid var(--brand);color:#fff}.secondary{background:#fff;border:1px solid var(--line);color:var(--ink)}.primary:disabled,.secondary:disabled{cursor:not-allowed;opacity:.55}.error,.loading{align-items:center;display:flex;gap:10px;min-height:220px;justify-content:center}.error{color:var(--bad)}@media (max-width:820px){body{background:#f7f9fa}.shell{padding:18px 12px 96px}.workspace{grid-template-columns:1fr}.topbar{margin-bottom:12px}.topbar p{display:none}.statsGrid{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin-bottom:14px}h1{font-size:24px;line-height:1.15}.iconButton{border-radius:10px;height:48px;width:48px}.workspace{display:flex;flex-direction:column;gap:12px}.questionPanel{order:1;padding:14px 14px 16px}.questionPanel,.sidePanel{border-radius:10px;width:100%}.sidePanel{order:2;padding:14px;margin-bottom:8px}.mobileProgress{align-items:center;background:#eef5f3;border:1px solid #d4e2df;border-radius:10px;color:var(--brand-dark);display:flex;font-size:15px;justify-content:space-between;margin-bottom:12px;padding:10px 12px}.mobileProgress strong{font-size:15px}h2{font-size:21px;line-height:1.38;margin-bottom:16px}.questionMeta{gap:8px;margin-bottom:14px}.questionMeta span{border-radius:999px;font-size:14px;padding:7px 12px}.options{gap:10px}.option{border-radius:10px;gap:12px;grid-template-columns:40px minmax(0,1fr);min-height:64px;padding:12px;font-size:18px;line-height:1.35}.optionLabel{border-radius:10px;height:40px;width:40px}.actions{background:rgba(247,249,250,.96);border-top:1px solid var(--line);bottom:0;gap:8px;left:0;margin-top:14px;padding:10px 12px calc(10px + env(safe-area-inset-bottom));position:fixed;right:0;z-index:10}.primary,.secondary{flex:1 1;min-height:48px;padding:0 12px;font-size:17px;font-weight:700}.stat{border-radius:10px;padding:12px}.stat strong{font-size:26px}.panelTitle{margin-top:2px}.typeRow{padding:10px 0}}