:root{font-family:system-ui,-apple-system,sans-serif;color-scheme:light dark}body{margin:0;display:flex;justify-content:center;padding:2rem 1rem}nav{position:fixed;top:1rem;display:flex;gap:1rem}.card{width:100%;max-width:360px;margin-top:2rem}form{display:flex;flex-direction:column;gap:.75rem}input,button{padding:.5rem;font-size:1rem}.error{color:#d33}