* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, #1a2a4a 0%, #2d4a7a 100%);
    color: #233;
}
.card {
    background: #fff;
    border-radius: 16px;
    padding: 40px 36px;
    width: min(92vw, 380px);
    box-shadow: 0 12px 40px rgba(0,0,0,.35);
    text-align: center;
}
h1 { font-size: 24px; margin-bottom: 8px; color: #1a2a4a; }
p.sub { font-size: 14px; color: #667; margin-bottom: 28px; }
input {
    width: 100%;
    font-size: 17px;
    padding: 12px 14px;
    border: 2px solid #ccd4e0;
    border-radius: 10px;
    margin-bottom: 16px;
    outline: none;
}
input:focus { border-color: #2d4a7a; }
button {
    width: 100%;
    font-size: 17px;
    font-weight: 600;
    padding: 13px;
    border: none;
    border-radius: 10px;
    background: #2d4a7a;
    color: #fff;
    cursor: pointer;
}
button:hover { background: #233c63; }
p.hint { font-size: 12px; color: #99a; margin-top: 18px; }