gistfile1.txt

.custom-icon1 {
    background-image: url('http://a.academia-assets.com/images/favicons/apple-touch-icon-144x144.png');
    display: block;
    height: 32px;
    width: 32px;
    background-size: cover;
}
.custom-icon2 {
    background-image: url('https://i1.rgstatic.net/ii/institution.image/AS%3A267458164789257%401440778403888_l');
    display: block;
    height: 32px;
    width: 32px;
    background-size: cover;
}