:root{color-scheme:dark;font-family:system-ui,sans-serif;color:#fff;background:#000}*{box-sizing:border-box}body{margin:0;font-size:1rem;line-height:1.5}main{padding:clamp(1.5rem,5vw,4rem)}h1{font-size:clamp(2rem,6vw,4rem)}