html,
body {
    height: 100%;
    margin: 0;
    padding: 15px;
    font-family: 'Arial', sans-serif;
    font-size: 12px;
}

main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.bookmark {
    width: 100%;
    max-width: 400px;
    aspect-ratio: 9 / 16;
    border: none;
    box-shadow: 0 0 30px 0 rgba(0, 0, 0, 0.2);
    border-radius: 20px;
    margin-bottom: 30px;
}