h2 {
    text-align: center;
}

main {
    max-width: 860px;
    margin: auto;
    padding: 1rem;
}

pre {
    display: flex;
    justify-content: space-around;
    align-items: stretch;
    border: 1px solid #999;
    background-color: #cbcbcb;
    overflow: hidden;
    padding-left: 1rem;
    padding-right: 1rem;
}

code {
    flex: 1;
    font-family: monospace;
    background-color: #cbcbcb;
    overflow-x: scroll;
    overflow-y: scroll;
}