:root{--bg:#0a0b10;--surface:#12141b;--surface-2:#0e1016;--line:#1c1f27;--line-2:#23262f;--line-3:#2a2e39;--fg:#eceef3;--fg-2:#c4c8d2;--muted:#9aa0ae;--dim:#858b99;--accent:#7c93ff;--bad:#ff6b6b;--easy:#4ade80;--medium:#f5c26b;--hard:#ff8a8a;--sans:"Geist", ui-sans-serif, system-ui, sans-serif;--mono:"Geist Mono", ui-monospace, monospace;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}*{box-sizing:border-box}body{background:var(--bg);color:var(--fg);font-family:var(--sans);-webkit-font-smoothing:antialiased;margin:0}button,select{font:inherit;color:inherit}button{cursor:pointer}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.page{flex-direction:column;gap:16px;max-width:1280px;min-height:100dvh;margin:0 auto;padding:32px 16px 28px;display:flex}.muted{color:var(--muted)}.top{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:16px;display:flex}.brand{align-items:center;gap:14px;display:flex}.logo{border:1px solid var(--line-3);width:44px;height:44px;font-family:var(--mono);color:var(--accent);border-radius:12px;place-items:center;font-size:14px;display:grid}h1{letter-spacing:-.02em;margin:0;font-size:24px;font-weight:600}.brand p{margin:2px 0 0;font-size:14px}.progress-box{min-width:200px;color:var(--muted);flex-direction:column;gap:6px;font-size:13px;display:flex}.progress-box strong{color:var(--fg);font-size:16px}.bar{background:var(--line-2);border-radius:3px;height:6px;overflow:hidden}.bar span{background:var(--accent);height:100%;transition:width .3s;display:block}.controls{border:1px solid var(--line);background:var(--surface-2);border-radius:16px;flex-wrap:wrap;align-items:flex-end;gap:10px;padding:14px;display:flex}.field{flex-direction:column;gap:4px;min-width:170px;display:flex}.field.grow{flex:260px}.field span{font-family:var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--dim);font-size:11px}select{border:1px solid var(--line-3);background:var(--surface);border-radius:10px;max-width:100%;height:40px;padding:0 10px;font-size:14px}.segmented{border:1px solid var(--line-3);border-radius:10px;height:40px;display:flex;overflow:hidden}.segmented button{border:0;border-right:1px solid var(--line-3);background:var(--surface);color:var(--muted);padding:0 12px;font-size:13px}.segmented button:last-child{border-right:0}.segmented button.active{color:var(--fg);background:#7c93ff29}.nav-buttons{gap:6px;display:flex}.filter-note{margin:-6px 0 0;font-size:12px}.btn{border:1px solid var(--line-3);background:var(--surface);border-radius:10px;justify-content:center;align-items:center;gap:10px;min-width:40px;height:40px;padding:0 14px;font-size:14px;font-weight:500;display:inline-flex}.btn:hover{border-color:#3a3f4d}.btn.primary{border-color:var(--accent);background:var(--accent);color:var(--bg);font-weight:600}.layout{grid-template-columns:minmax(0,380px) minmax(0,1fr);align-items:start;gap:16px;display:grid}.problem{border:1px solid var(--line-2);background:var(--surface);border-radius:18px;max-height:calc(100dvh - 32px);padding:22px;position:sticky;top:16px;overflow-y:auto}.meta{font-family:var(--mono);color:var(--dim);margin:0;font-size:12px}.problem h2{letter-spacing:-.02em;margin:8px 0 10px;font-size:22px;font-weight:600}.problem h3{font-size:13px;font-family:var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--accent);margin:20px 0 6px}.problem p{color:var(--fg-2);margin:8px 0;font-size:14px;line-height:1.65}.problem p.example{background:var(--surface-2);font-family:var(--mono);overflow-wrap:anywhere;border-radius:10px;padding:10px 12px;font-size:12.5px}.problem code{background:var(--line-2);font-family:var(--mono);color:var(--fg);border-radius:4px;padding:1px 5px;font-size:.9em}.badges{gap:6px;display:flex}.badge{border:1px solid;border-radius:999px;padding:3px 9px;font-size:12px;font-weight:500}.badge.easy{color:var(--easy)}.badge.medium{color:var(--medium)}.badge.hard{color:var(--hard)}.badge.done{color:var(--accent)}.complexity{grid-template-columns:1fr 1fr;gap:8px;margin:20px 0 0;display:grid}.complexity div{border:1px solid var(--line);border-radius:10px;padding:10px 12px}.complexity dt{font-family:var(--mono);text-transform:uppercase;color:var(--dim);font-size:11px}.complexity dd{font-family:var(--mono);margin:4px 0 0;font-size:13px}.workspace{flex-direction:column;gap:12px;min-width:0;display:flex}.stats{border:1px solid var(--line);background:var(--surface-2);border-radius:14px;grid-template-columns:repeat(4,minmax(0,1fr));margin:0;display:grid;overflow:hidden}.stats>div{border-right:1px solid var(--line);padding:12px 16px}.stats>div:last-child{border-right:0}.stats dt{font-family:var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--dim);font-size:11px}.stats dd{font-variant-numeric:tabular-nums;margin:4px 0 0;font-size:24px;font-weight:600}.result{border:1px solid var(--accent);background:#7c93ff14;border-radius:16px;flex-direction:column;align-items:center;gap:16px;padding:22px;animation:.3s ease-out fade;display:flex}.result-title{margin:0;font-size:20px;font-weight:600}.result-grid{text-align:center;grid-template-columns:repeat(4,minmax(70px,1fr));gap:20px;display:grid}.result-grid strong{letter-spacing:-.03em;font-variant-numeric:tabular-nums;font-size:30px;font-weight:600;display:block}.result-grid span{color:var(--muted);font-size:13px}.result-actions{flex-wrap:wrap;justify-content:center;gap:10px;display:flex}@keyframes fade{0%{opacity:0}}.editor{border:1px solid var(--line-3);background:var(--surface);cursor:text;border-radius:16px;position:relative;overflow:hidden}.editor:focus-within{border-color:#3a3f4d}.editor-bar{border-bottom:1px solid var(--line-2);background:var(--surface-2);font-family:var(--mono);color:var(--muted);align-items:center;gap:14px;padding:11px 16px;font-size:12px;display:flex}.dots{gap:6px;display:flex}.dots i{background:var(--line-3);border-radius:50%;width:10px;height:10px}.progress{background:var(--line-2);border-radius:2px;width:120px;height:4px;margin-left:auto;overflow:hidden}.progress span{background:var(--accent);height:100%;transition:width .15s;display:block}.code{font-family:var(--mono);margin:0;padding:18px 0;font-size:14.5px;line-height:1.75;overflow-x:auto}.line{white-space:pre;padding-right:20px;display:flex}.gutter{text-align:right;width:48px;color:var(--line-3);-webkit-user-select:none;user-select:none;flex:none;padding-right:16px}.todo{color:var(--dim)}.ok{color:var(--fg)}.bad{color:var(--bad);background:#ff6b6b2e;border-radius:3px}.caret{color:var(--dim);box-shadow:inset 2px 0 0 var(--accent);animation:1s step-end infinite blink}.nl{opacity:.45;font-size:12px}.nl.ok{color:var(--dim)}@keyframes blink{50%{box-shadow:inset 2px 0 #0000}}.sr-input{opacity:0;resize:none;pointer-events:none;position:absolute;inset:0}.start-hint{color:var(--dim);margin:0;padding:0 20px 16px 64px;font-size:13px}kbd{border:1px solid var(--line-3);font-family:var(--mono);border-radius:5px;padding:2px 6px;font-size:11px}.btn.primary kbd{border-color:#0a0b104d}.keys{text-align:center;margin:0;font-size:13px}footer{text-align:center;margin-top:auto;padding-top:12px;font-size:13px}footer a{color:var(--fg-2)}@media (width<=900px){.layout{grid-template-columns:minmax(0,1fr)}.problem{max-height:none;position:static}}@media (width<=640px){.field{flex:100%}.segmented{flex:auto}.segmented button{flex:1}.stats{grid-template-columns:repeat(2,minmax(0,1fr))}.stats>div:nth-child(2){border-right:0}.stats>div:nth-child(-n+2){border-bottom:1px solid var(--line)}.code{font-size:12.5px}.gutter{width:34px;padding-right:10px}.start-hint{padding-left:20px}.result-grid{grid-template-columns:repeat(2,minmax(70px,1fr))}}@media (prefers-reduced-motion:reduce){*,:before,:after{transition:none!important;animation:none!important}}.side{flex-direction:column;align-items:stretch;gap:10px;min-width:min(100%,360px);display:flex}.segmented.languages button{font-family:var(--mono);flex:1;justify-content:center;align-items:center;gap:6px;display:inline-flex}.segmented.languages .count{background:var(--line-2);min-width:18px;color:var(--dim);border-radius:6px;padding:1px 5px;font-size:11px}.segmented.languages button.active .count{color:var(--fg);background:#7c93ff40}@media (width<=640px){.side{width:100%}.segmented.languages button{padding:0 6px;font-size:12px}}