body{margin:0;font-family:Arial;background:#0b0f1a;color:#fff}
.center{display:flex;justify-content:center;align-items:center;height:100vh}
.card{background:#11162a;padding:40px;border-radius:12px;width:320px;text-align:center}
input,button{width:100%;padding:10px;margin:8px 0;border:none;border-radius:6px}
button{background:#3b82f6;color:#fff}
header{display:flex;justify-content:space-between;padding:15px;background:#11162a}