pruncalc/styles.css

* {
    box-sizing: border-box;
}

body {
    font-family: monospace;
    font-size: 14pt;
    background-color: #000;
    color: #eee;
}

main {
    max-width: 1200px;
    margin: 1em auto;
    padding: 1em;
    background: #111;
}

td {
    text-align: right;
    padding: 0.25em 1em;
}
td:first-child {
    text-align: inherit;
}