*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,sans-serif;background:#f4f4f5;color:#18181b;line-height:1.45}main{max-width:760px;margin:0 auto;padding:16px}h1{font-size:20px;margin:8px 0 16px}button{cursor:pointer}button,input{font:inherit}