.light {
    background-color: #000;
    box-shadow: 0 0 5px rgba(0,0,0, .8);
    overflow: hidden;
    padding: 0 0 4px;
    width: 40px;
}

.light span {
    border-radius: 50px;
    display: block;
    height: 30px;
    margin: 4px auto 0;
    opacity: .2;
    width: 30px;
}

/*! Light colours */
.red    { background-color: red; }
.orange { background-color: orange; }
.green  { background-color: lime; }

/*! Active states */
.light span.active    { opacity: 1; }
.light .red.active    { box-shadow: 0 0 10px red; }
.light .orange.active { box-shadow: 0 0 10px yellow; }
.light .green.active  { box-shadow: 0 0 10px lime; }