:root{color-scheme:dark;font-family:Inter,system-ui,sans-serif;background:#101413;color:#e7f0ea}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:radial-gradient(circle at top,#183029,#101413 55%)}main{min-height:100vh;display:grid;place-items:center;padding:20px}.card{width:min(520px,100%);padding:28px;border:1px solid #2a3d36;border-radius:18px;background:#17201d;box-shadow:0 16px 45px #0005;text-align:center}h1{margin:0 0 18px;font-size:clamp(1.7rem,5vw,2.5rem)}p{margin:0;color:#b9cbc1;line-height:1.5}button{margin-top:20px;border:0;border-radius:10px;padding:11px 17px;background:#39b982;color:#07120d;font-weight:700;cursor:pointer}