#content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 3fr 1fr;
    gap: 1rem;
    margin: 1rem auto;
    width: 20em;
    text-align: center;
}

#content,
#content * {
    font-size: 1.15em;
}

#result
,#reset {
    grid-column: 1 / span 2;
}