:root{font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif}body{margin:0;background:#f6f6f6;color:#111}#app{max-width:1100px;margin:0 auto;padding:16px;display:grid;gap:12px}header{display:flex;flex-wrap:wrap;gap:12px 16px;align-items:center;padding:12px;background:#fff;border-radius:10px}label{display:inline-flex;gap:8px;align-items:center}main{padding:12px;background:#fff;border-radius:10px}canvas{width:100%;height:auto;display:block;border-radius:8px;background:#fff}footer{padding:10px 12px;background:#fff;border-radius:10px;font-size:14px;color:#333}