:root{--bg:#f4f5f2;--fg:#1f2421;--muted:#5d665f;--panel:#fff;--border:#d5d9d3;--accent:#2f6f3a;--accent-fg:#fff;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,sans-serif}@media (prefers-color-scheme:dark){:root{--lightningcss-light: ;--lightningcss-dark:initial;--bg:#171a18;--fg:#e7ebe6;--muted:#9aa49c;--panel:#222624;--border:#3a403b;--accent:#4f9c5c}}*{box-sizing:border-box}body{background:var(--bg);color:var(--fg);margin:0;padding:16px}header,main{max-width:960px;margin:0 auto}h1{margin:0 0 4px;font-size:1.5rem}header p,.help{color:var(--muted);margin:0 0 16px}.help{margin-top:12px;font-size:.9rem}.canvas-wrap{aspect-ratio:4/3;border:1px solid var(--border);border-radius:6px;width:100%;max-width:93.3333vh;max-height:70vh;margin:0 auto;position:relative;overflow:hidden}#track-canvas{touch-action:none;cursor:crosshair;width:100%;height:100%;display:block}.hint{pointer-events:none;color:#fff;text-shadow:0 1px 4px #0009;place-items:center;font-size:1.4rem;font-weight:600;display:grid;position:absolute;inset:0}.hint[hidden]{display:none}.toolbar{background:var(--panel);border:1px solid var(--border);border-radius:6px;flex-wrap:wrap;align-items:center;gap:8px 16px;margin-top:12px;padding:10px 12px;display:flex}.field,.check{align-items:center;gap:8px;display:inline-flex}.label{font-weight:600}.spacer{flex:1}button{font:inherit;border:1px solid var(--border);background:var(--panel);color:var(--fg);cursor:pointer;border-radius:5px;padding:6px 14px}button.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-fg)}button:disabled{opacity:.45;cursor:not-allowed}