:root{--ground:#f4f0ec;--surface:#fff;--surface-2:#ece7e1;--ink:#1b1c21;--muted:#63666e;--faint:#9a9ca3;--border:#e4ded7;--border-strong:#d6cfc6;--accent:#e9524e;--accent-text:#c13e3b;--accent-wash:#faedeb;--btn:#cf4440;--btn-hover:#c13e3b;--good:#2e9e76;--good-wash:#e7f4ee;--good-text:#1e7a57;--shadow:0 1px 2px #281e1a0d, 0 10px 26px #281e1a12;--radius:14px;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--ground:#191c22;--surface:#22262e;--surface-2:#2a2f38;--ink:#ecedef;--muted:#a2a6ae;--faint:#6e727c;--border:#30353f;--border-strong:#3c424d;--accent:#ff6b67;--accent-text:#ff8480;--accent-wash:#2c2022;--btn:#cf4440;--btn-hover:#c13e3b;--good:#3fb98c;--good-wash:#16241e;--good-text:#3fb98c;--shadow:0 1px 2px #00000047, 0 14px 32px #00000057;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}}:root[data-theme=dark]{--ground:#191c22;--surface:#22262e;--surface-2:#2a2f38;--ink:#ecedef;--muted:#a2a6ae;--faint:#6e727c;--border:#30353f;--border-strong:#3c424d;--accent:#ff6b67;--accent-text:#ff8480;--accent-wash:#2c2022;--btn:#cf4440;--btn-hover:#c13e3b;--good:#3fb98c;--good-wash:#16241e;--good-text:#3fb98c;--shadow:0 1px 2px #00000047, 0 14px 32px #00000057;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}*{box-sizing:border-box}body{background:var(--ground);color:var(--ink);-webkit-font-smoothing:antialiased;text-rendering:optimizelegibility;min-height:100vh;margin:0;font:15px/1.5 ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.app{max-width:720px;margin:0 auto;padding:0 20px 64px}.topbar{justify-content:space-between;align-items:center;padding:18px 0 16px;display:flex}.brand{align-items:center;gap:11px;display:flex}.brand img{width:30px;height:30px;display:block}.brand-name{letter-spacing:.02em;color:var(--ink);font-size:13px;font-weight:600}.brand-sub{color:var(--muted);border-left:1px solid var(--border-strong);padding-left:11px;font-size:12px}.controls{align-items:center;gap:8px;display:flex}.icon-btn,.ghost{font:inherit;color:var(--muted);border:1px solid var(--border);cursor:pointer;background:0 0;border-radius:9px;align-items:center;gap:7px;height:34px;transition:border-color .15s,color .15s,background .15s;display:inline-flex}.icon-btn{justify-content:center;width:34px;padding:0}.ghost{padding:0 13px;font-size:13px;font-weight:500}.icon-btn:hover,.ghost:hover{color:var(--ink);border-color:var(--border-strong);background:var(--surface-2)}.icon-btn svg{width:16px;height:16px}.tabs{border-bottom:1px solid var(--border);gap:2px;margin-bottom:26px;display:flex}.tab{font:inherit;color:var(--muted);cursor:pointer;background:0 0;border:0;align-items:center;gap:8px;padding:10px 15px 13px;font-size:13px;font-weight:500;display:flex;position:relative}.tab.active{color:var(--ink)}.tab.active:after{content:"";background:var(--accent);border-radius:2px;height:2px;position:absolute;bottom:-1px;left:12px;right:12px}.tab[aria-disabled=true]{color:var(--faint);cursor:not-allowed}.chip{letter-spacing:.08em;text-transform:uppercase;color:var(--muted);background:var(--surface-2);border:1px solid var(--border);border-radius:20px;padding:2px 7px;font-size:10px;font-weight:600}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}.card-head{padding:22px 24px 4px}.card-head h1{letter-spacing:-.01em;color:var(--ink);margin:0;font-size:19px;font-weight:600}.card-head p{color:var(--muted);margin:6px 0 0;font-size:13px}.card-body{flex-direction:column;gap:14px;padding:20px 24px 24px;display:flex}.drop{border:1px solid var(--border-strong);background:var(--surface-2);border-radius:11px;align-items:center;gap:14px;padding:15px 16px;transition:border-color .15s,background .15s;display:flex}.drop.filled{border-color:var(--good);background:var(--good-wash)}.drop.dragover{border-color:var(--accent);background:var(--accent-wash)}.num{background:var(--surface);border:1px solid var(--border-strong);width:26px;height:26px;color:var(--muted);font-variant-numeric:tabular-nums;border-radius:7px;flex:none;place-items:center;font-size:13px;font-weight:600;display:grid}.drop.filled .num{background:var(--good);border-color:var(--good);color:#fff}.meta{flex:1;min-width:0}.drop .label{color:var(--ink);font-size:13px;font-weight:500;display:block}.hint{color:var(--muted);white-space:nowrap;text-overflow:ellipsis;margin-top:1px;font-size:12px;overflow:hidden}.drop.filled .hint{color:var(--good-text)}.choose{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--border-strong);cursor:pointer;border-radius:8px;flex:none;padding:7px 12px;font-size:13px;font-weight:500}.choose:hover{border-color:var(--accent);color:var(--accent-text)}.drop input[type=file]{opacity:0;width:1px;height:1px;position:absolute}.drop:focus-within .choose{outline:2px solid var(--accent);outline-offset:2px}.solve{font:inherit;color:#fff;background:var(--btn);cursor:pointer;border:0;border-radius:11px;margin-top:4px;padding:13px;font-size:15px;font-weight:600;transition:background .15s,transform 50ms}.solve:hover:not(:disabled){background:var(--btn-hover)}.solve:active:not(:disabled){transform:translateY(1px)}.solve:disabled{background:var(--surface-2);color:var(--muted);cursor:not-allowed;border:1px solid var(--border)}.helper{color:var(--muted);text-align:center;margin-top:-4px;font-size:12px}.state{border-top:1px solid var(--border);padding:20px 24px}.solving{align-items:center;gap:14px;display:flex}.spinner{border:2.5px solid var(--accent-wash);border-top-color:var(--accent);border-radius:50%;flex:none;width:26px;height:26px;animation:.8s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.35}}@media (prefers-reduced-motion:reduce){.spinner{border-top-color:var(--accent-wash);background:var(--accent);border-width:0;animation:1.4s ease-in-out infinite pulse}}.txt{flex:1;min-width:0}.t1{font-size:15px;font-weight:600}.t2{color:var(--muted);margin-top:1px;font-size:12px}.timer{font-variant-numeric:tabular-nums;color:var(--accent-text);letter-spacing:.02em;flex:none;font-size:15px;font-weight:600}.row{align-items:center;gap:12px;margin-bottom:16px;display:flex}.row-end{margin-left:auto}.badge{border-radius:50%;flex:none;place-items:center;width:28px;height:28px;display:grid}.badge svg{stroke:#fff;width:15px;height:15px}.done-badge{background:var(--good)}.fail-badge{background:var(--accent)}.st1{font-size:15px;font-weight:600}.st2{color:var(--muted);margin-top:1px;font-size:12px}.st2 b{color:var(--good-text);font-variant-numeric:tabular-nums;font-weight:600}.actions{flex-wrap:wrap;gap:10px;display:flex}.primary{font:inherit;color:#fff;background:var(--btn);cursor:pointer;border:0;border-radius:10px;align-items:center;gap:8px;padding:11px 18px;font-size:15px;font-weight:600;display:inline-flex}.primary:hover{background:var(--btn-hover)}.primary svg{stroke:currentColor;width:16px;height:16px}.login-card{max-width:380px;margin:40px auto 0}.login-card h1{color:var(--ink);margin:0;padding:24px 24px 0;font-size:19px;font-weight:600}.login-card .card-body{padding:16px 24px 24px}.field{font:inherit;color:var(--ink);background:var(--surface-2);border:1px solid var(--border-strong);border-radius:10px;padding:12px 14px;font-size:15px}.login-error{color:var(--accent-text);margin:0;font-size:13px}