html, body {
    height: 100%;
    margin: 0;
}

body {
    background: url(assets/background.png);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.tile {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    height: 500px;
    max-width: 90vw;
    max-height: 90vh;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
    padding: 10px;
}