.displayNone {
    display: none;
}

.displayBlock {
    display: block;
}

.mainTable {
    border-color: black;
    border-collapse: collapse;
}

    .mainTable td {
        border: 1px solid black;
    }

    .mainTable th {
        border: 1px solid black;
        background: #b0e0e6;
    }

.powerIsOffTd {
    background: #ff0000;
}