:root,[data-theme=dark]{--bg:#111827;--surface:#1f2937;--track:#374151;--text:#f9fafb;--text-muted:#9ca3af;--text-subtle:#6b7280;--accent:#fbbf24;--btn-bg:#f59e0b;--btn-bg-hover:#fbbf24;--btn-text:#111827;--focus-ring:#fbbf24;--focus-offset:#111827}[data-theme=light]{--bg:#f3f4f6;--surface:#e5e7eb;--track:#d1d5db;--text:#111827;--text-muted:#4b5563;--text-subtle:#374151;--accent:#d97706;--btn-bg:#f59e0b;--btn-bg-hover:#fbbf24;--btn-text:#111827;--focus-ring:#d97706;--focus-offset:#f3f4f6}:root{--status-solved:#16a34a;--status-failed:#dc2626;--status-progress:#2563eb;--status-idle:#6b7280;--feedback-correct:#22c55e;--feedback-incorrect:#ef4444;--board-dark:#769656;--board-light:#eeeed2;--space-1:.375rem;--space-2:.5rem;--space-3:.75rem;--space-4:1rem;--space-6:1.5rem;--space-8:2rem;--radius-sm:.375rem;--radius-md:.75rem;--radius-lg:1rem;--radius-xl:1.5rem;--radius-full:9999px;--board-max:520px}
*,:before,:after{box-sizing:border-box}html,body{margin:0;padding:0}body{background:var(--bg);color:var(--text);font-family:Arial,Helvetica,sans-serif;transition:background-color .2s,color .2s}
.theme-toggle{top:var(--space-4);right:var(--space-4);z-index:20;padding:var(--space-2);border-radius:var(--radius-md);background:var(--surface);color:var(--text);cursor:pointer;border:0;justify-content:center;align-items:center;transition:background-color .15s,filter .15s;display:inline-flex;position:fixed}.theme-toggle:hover{filter:brightness(.92)}.theme-toggle:focus-visible{box-shadow:0 0 0 2px var(--focus-ring);outline:none}.theme-toggle__icon{width:1.25rem;height:1.25rem}.theme-toggle--placeholder{pointer-events:none;background:0 0;width:2.5rem;height:2.5rem}
.sound-toggle{top:var(--space-4);right:calc(var(--space-4) + 2.75rem);z-index:20;padding:var(--space-2);border-radius:var(--radius-md);background:var(--surface);color:var(--text);cursor:pointer;border:0;justify-content:center;align-items:center;transition:background-color .15s,filter .15s;display:inline-flex;position:fixed}.sound-toggle:hover{filter:brightness(.92)}.sound-toggle:focus-visible{box-shadow:0 0 0 2px var(--focus-ring);outline:none}.sound-toggle__icon{width:1.25rem;height:1.25rem}.sound-toggle--placeholder{pointer-events:none;background:0 0;width:2.5rem;height:2.5rem}
.feedback-toggle{top:var(--space-4);right:calc(var(--space-4) + 5.5rem);z-index:20;padding:var(--space-2);border-radius:var(--radius-md);background:var(--surface);color:var(--text);cursor:pointer;border:0;justify-content:center;align-items:center;transition:background-color .15s,filter .15s;display:inline-flex;position:fixed}.feedback-toggle:hover{filter:brightness(.92)}.feedback-toggle:focus-visible{box-shadow:0 0 0 2px var(--focus-ring);outline:none}.feedback-toggle__icon{width:1.25rem;height:1.25rem}