td, th {
    text-align: center;
    padding: 2px;
    white-space: nowrap; 
    font-size: 12px;
}

th {
    background-color: teal;
}

td.problem {
    background-color: #ffff99;
}

td.keys {
    font-weight: normal;
    font-family: monospace;
    background-color: #cccccc;
}

td.tape {
    text-align: right;
    font-weight: bold;
    font-family: monospace;
    background-color: white;
}

td.display {
    text-align: right;
    font-weight: bold;
    font-family: monospace;
    color: lime;
    background-color: black;
}

body {
    color: black; 
    background-color: #ffffcc;
}