* {
    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        "Apple Color Emoji",
        "Segoe UI Emoji",
        "Segoe UI Symbol",
        sans-serif;
}

#container {
    height: 300px;
    max-width: 800px;
    margin: 2em auto;
}

.controls {
    margin: 0 10px;
}

pre {
    border: 1px solid silver;
    border-radius: 0.5em;
    padding: 1em;
    color: green;
}
