:root{color-scheme:light dark}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;display:flex;min-height:100vh;align-items:center;justify-content:center;background:#f5f5f7}main{text-align:center;padding:2.5rem 3rem;background:#fff;border-radius:12px;box-shadow:0 1px 3px rgba(0,0,0,.1);max-width:420px}button{font-size:1rem;padding:.6rem 1.2rem;border-radius:8px;border:none;background:#2f2f2f;color:#fff;cursor:pointer;margin-top:1rem}button:hover{background:#444}p.subtitle{color:#666;font-size:.95rem}