.layout {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    width: 500px;
    margin: 0 auto;
    gap: 10px;
}

header,
footer {
    text-align: center;
}

header,
main,
footer {
    background-color: var(--content-background-color);
    border: var(--border);
    border-radius: var(--round-borders);
}

main {
    padding: 10px
}