body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #1f2937, #111827);
    color: #f9fafb;
}
.wrap { width: min(92vw, 560px); padding: 20px; }
.card {
    background: rgba(255,255,255,.06);
    border: 1px solid rgba(255,255,255,.12);
    border-radius: 16px;
    padding: 28px;
    text-align: center;
}
h1 { margin: 0 0 12px; font-size: 1.6rem; }
p  { margin: 0 0 10px; color: #d1d5db; }
small { color: #9ca3af; }