style.css

body {
    background-color: #222222;
    color: white;
    font-family: Consolas, Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono, Bitstream Vera Sans Mono, Courier New, monospace, serif;
}

textarea {
    width: 98%;
    box-sizing: border-box;
    padding: 5px;
    margin: 5px;
    color: white;
    background-color: black;
    border: 1px solid grey;
    border-radius: 3px;
    font-family: Consolas, Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono, Bitstream Vera Sans Mono, Courier New, monospace, serif;
    font-size: 10pt;
}

div {
    padding: 5px;
    margin: 5px;
    background-color: black;
    border: 1px solid grey;
    border-radius: 3px;
    font-size: 10pt;
}

a {
    color: #AAF;
}

#path {
    color: lightblue;
}

#filename {
    text-decoration: underline;
    text-decoration-style: dotted;
    text-decoration-color: #488;
}

#insid {
    color: #FFFFAA;
}

#error {
    color: #FF3333;
    font-weight: bolder;
}

#warning {
    color: #FFCC33;
    font-weight: bolder;
}

#loc {
    color: #BBF;
}

#namespace {
    text-decoration: underline;
    text-decoration-style: dotted;
    text-decoration-color: #BBB;
}

hr.file {
    padding: 2pt;
    border: none;
    border-top: medium double #CCC;
    color: #CCC;
}

#output {
    margin-left: 12pt;
    white-space: pre-wrap;
    display: block;
}

#input {
    margin-left: 12pt;
}

#navi {
    position: fixed;
    z-index: 100;
    left: 2px;
    top: 20pt;
    font-size: 8pt;
}