span.helloworld {
    color: red;
    font-weight: bold;
}
span.helloworld::before {
    background: url('logo-atreal.png');
    background-color: blue;
    background-size: 16px 16px;
    content: " ";
    display: block;
    float: left;
    height: 16px;
    width: 16px;
}