article {
    max-width: 25em;
}

#display {
    font-size: 150%;
    height: 100px;
}

.centered {
    text-align: center;
}

#buttons {
    padding: 0.5em;
    display: flex;
    justify-content: center;
    align-items: stretch;
    gap: 1.5em;
}

#buttons button {
    min-height: 2em;
    display: inline-flex;
    align-items: center;
    gap: 0.2em;
}

#buttons img {
    width: auto;
    height: 1em;
    display: block;
}