main.css

html, body {
    height: 100%;
    width: 100%;
    margin: 0;
    font-family: Helvetica Neue, Lucida Grande, Segoe UI, Tahoma, sans;
    font-size: 16px;
    background: #EDEDED;
}

section {
    padding: 1em 1em 0;
}

section .buttons-group {
    margin-bottom: 1em;
}

section .buttons-group h5 {
    margin-top: 0;
    margin-bottom: 0.65em;
}

#output {
    margin-top: 20px;
    box-sizing: border-box;
    padding: 5px;
    font-size: 12px;
    font-family: Consolas, "Liberation Mono", Menlo, Courier, monospace;
    background: #fff;
    border: 1px solid #BEBEBE;
    height: 248px;
    max-height: 248px;
    overflow: auto;
}

#output span.error {
    color: red;
}
#output span.data {
    color: deepskyblue;
}
#output span.command {
    color: blue;
}
video {
    display: block;
}