/* Touch ID icon as CSS background */
.touchid-icon {
    display: inline-block;
    width: 24px;
    height: 24px;
    background-image: url('touchid-icon.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    vertical-align: middle;
    margin-right: 8px;
}