:root{--primary:#04667f;--primary-dark:#034a5d;--primary-light:#8ad8ee;--accent:#f2b705;--ink:#0b1822;--surface:#fafaf9;--tint:#f1f7fa;--muted:#4a5c68;--line:#d5e2e8;--right:#1e7b4f;--right-bg:#e6f4ec;--wrong:#b3261e;--wrong-bg:#fbeae8;--radius:14px;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{background:var(--surface);color:var(--ink);margin:0;font:17px/1.5 system-ui,-apple-system,Segoe UI,Roboto,Noto Sans Bengali,Noto Sans,sans-serif}main{max-width:560px;margin:0 auto;padding:0 16px 40px}a{color:var(--primary)}h1{margin:0;font-size:1.5rem;line-height:1.25}h2{margin:24px 0 8px;font-size:1.15rem}p{margin:8px 0}.muted{color:var(--muted)}.small{font-size:.9rem}.top{z-index:5;background:var(--primary);color:#fff;position:sticky;top:0}.top .bar{align-items:center;gap:10px;max-width:560px;min-height:56px;margin:0 auto;padding:10px 16px;display:flex}.top .title{flex:1;font-size:1.05rem;font-weight:700}.top a,.top button.link{color:#fff;font-weight:600;text-decoration:none}.top .back{padding:4px 8px 4px 0;font-size:1.4rem}.btn{border-radius:var(--radius);cursor:pointer;background:var(--primary);color:#fff;width:100%;min-height:52px;font:inherit;border:0;justify-content:center;align-items:center;gap:8px;padding:12px 16px;font-weight:700;text-decoration:none;display:flex}.btn:active{background:var(--primary-dark)}.btn.secondary{background:var(--tint);color:var(--primary-dark);border:1px solid var(--line)}.btn:disabled{opacity:.5;cursor:default}.btn+.btn{margin-top:10px}:focus-visible{outline:3px solid var(--primary-dark);outline-offset:2px}.card{border:1px solid var(--line);border-radius:var(--radius);color:inherit;background:#fff;margin:12px 0;padding:16px;text-decoration:none;display:block}a.card:active{background:var(--tint)}.card .name{font-size:1.1rem;font-weight:700}.meter{background:var(--tint);border-radius:4px;height:8px;margin-top:10px;overflow:hidden}.meter>i{background:var(--primary);height:100%;display:block}.choice{gap:10px;margin:8px 0 16px;display:grid}.choice label{border:2px solid var(--line);border-radius:var(--radius);cursor:pointer;background:#fff;align-items:center;gap:10px;min-height:52px;padding:10px 14px;display:flex}.choice input{width:20px;height:20px;accent-color:var(--primary)}.choice label:has(input:checked){border-color:var(--primary);background:var(--tint)}.tabs{gap:8px;margin:16px 0 4px;display:flex}.tabs button{border:1px solid var(--line);min-height:48px;font:inherit;color:var(--muted);cursor:pointer;background:#fff;border-radius:999px;flex:1;font-weight:600}.tabs button[aria-selected=true]{background:var(--primary);border-color:var(--primary);color:#fff}.chapters{margin:8px 0 16px;padding:0;list-style:none}.chapters li a,.chapters li .off{border-bottom:1px solid var(--line);min-height:56px;color:inherit;align-items:center;gap:12px;padding:14px 4px;text-decoration:none;display:flex}.chapters .n{text-align:right;width:28px;color:var(--muted);font-variant-numeric:tabular-nums}.chapters .label{flex:1}.chapters .count{color:var(--muted);white-space:nowrap;font-size:.9rem}.chapters .off{color:var(--muted)}.progress{background:var(--tint);height:6px}.progress>i{background:var(--primary-light);height:100%;transition:width .2s;display:block}.q{margin:20px 0 16px;font-size:1.15rem;font-weight:600}.opts{gap:10px;display:grid}.opt{border:2px solid var(--line);border-radius:var(--radius);width:100%;min-height:56px;color:var(--ink);font:inherit;text-align:left;cursor:pointer;background:#fff;align-items:flex-start;gap:12px;padding:12px 14px;display:flex}.opt .l{background:var(--tint);width:28px;height:28px;color:var(--primary-dark);border-radius:50%;flex:none;place-items:center;font-size:.95rem;font-weight:700;display:grid}.opt .txt{flex:1;padding-top:1px}.opt .mark{flex:none;font-weight:700}.opt.chosen{border-color:var(--primary);background:var(--tint)}.opt.right{border-color:var(--right);background:var(--right-bg)}.opt.right .mark{color:var(--right)}.opt.wrong{border-color:var(--wrong);background:var(--wrong-bg)}.opt.wrong .mark{color:var(--wrong)}.opt:disabled{cursor:default}.feedback{border-radius:var(--radius);border:1px solid var(--line);background:#fff;margin:16px 0;padding:14px 16px}.feedback .verdict{font-weight:700}.feedback .verdict.ok{color:var(--right)}.feedback .verdict.no{color:var(--wrong)}.draft{color:var(--muted);border:1px dashed var(--muted);border-radius:999px;margin-top:18px;padding:2px 10px;font-size:.85rem;display:inline-block}.stickybottom{background:linear-gradient(transparent, var(--surface) 30%);padding:12px 0;position:sticky;bottom:0}.big{color:var(--primary-dark);margin:8px 0;font-size:2rem;font-weight:800}.nav{grid-template-columns:repeat(auto-fill,minmax(44px,1fr));gap:8px;margin:16px 0;display:grid}.nav button{border:1px solid var(--line);min-height:44px;font:inherit;cursor:pointer;background:#fff;border-radius:10px}.nav button.done{background:var(--tint);border-color:var(--primary-light)}.nav button.here{outline:3px solid var(--primary)}.timer{font-variant-numeric:tabular-nums;font-weight:700}.timer.low{color:var(--accent)}.skeleton{background:linear-gradient(90deg, var(--tint), #e4eef2, var(--tint));border-radius:6px;height:1.2em;margin:10px 0}footer{text-align:center;padding:24px 16px}.sr{clip:rect(0 0 0 0);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}