:root{--panel-bg: #f5f6f7;--border: #d0d4d9;--accent: #2563eb;--ok: #1a7f37;--error: #b00020;--canvas-bg: #000}*{box-sizing:border-box}html,body{height:100%;margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,sans-serif;font-size:15px;color:#1c1e21}button{font:inherit;padding:.4rem .8rem;border:1px solid var(--border);border-radius:4px;background:#fff;cursor:pointer}button:hover:not(:disabled){background:#eef1f4}button:disabled{opacity:.5;cursor:default}button.primary{background:var(--accent);border-color:var(--accent);color:#fff}button.primary:hover:not(:disabled){background:#1d4ed8}.banner{margin:0;padding:.5rem .7rem;border-radius:4px;font-size:.85rem;background:#eef1f4}.banner.error{background:#fdecea;color:var(--error)}.banner.ok{background:#e6f4ea;color:var(--ok)}