body{font-family:Segoe UI, Roboto, Arial, sans-serif;line-height:1.4;margin:0;padding:1rem;background:#f6f8fa;color:#0b0b0b}
main{max-width:720px;margin:2rem auto;padding:1.5rem;background:#fff;border-radius:8px;box-shadow:0 4px 14px rgba(11,11,11,0.06)}
h1{margin:0 0 .5rem}
#preview{margin-top:1rem}
#preview img{display:block;border-radius:6px}