:root{color-scheme:dark;font-family:system-ui,sans-serif;background:#101719;color:#f3f6f3}body{margin:0}main{max-width:640px;margin:40px auto;padding:24px}h1{font-size:clamp(22px,5.5vw,28px)}p{line-height:1.7}section{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:24px 0}button{padding:16px;border:1px solid #6b8275;border-radius:12px;background:#173c2d;color:#fff;font:inherit;cursor:pointer}button:focus-visible{outline:3px solid #f6d479}a{color:#c8e3d4}input[type=range]{max-width:50vw;vertical-align:middle}