:root{font-family:system-ui,sans-serif;color:#e6edf3;background:#111c27;color-scheme:dark}body{margin:0;padding:6vh 6vw}main{max-width:760px;margin:auto}h1{font-size:clamp(2rem,5vw,3.5rem);line-height:1.1}p{line-height:1.6;color:#bbcad7}.controls{display:flex;gap:12px;flex-wrap:wrap;margin:2rem 0}button{padding:14px 18px;border:1px solid #758a9d;border-radius:8px;background:#20364a;color:white;font:inherit;cursor:pointer}button:disabled{opacity:.45;cursor:default}button:focus-visible{outline:3px solid #78c8de}#start{background:#186e80}#status{color:#8fe3cc}#error{color:#ffb6a9}.note{font-size:.88rem}