body{
    background-color: #343D46;
    font-family: Arial, Helvetica, sans-serif;

}
.holder{
    margin: auto;
    max-width: 800px;
}
.keys {
    text-align: center;
}
.keys li{
    padding: 60px 10px;
    background-color: #666;
    text-align: center;
    color: #999;
    list-style-type: none;
    display:inline-block;
    margin: 2px;
    cursor: pointer;
    text-transform: uppercase;
}

.pressed{
    background-color: #000 !important;
    padding-bottom: 90px !important;
}