Social Widget in Header not mobile friendly

@Kim: It’s because you have added that Social Icons Widgets in Header Top Sidebar and also added custom css to position it as absolute 30px. See the following custom css that you have added

#sidebar-header-top {
    position: absolute;
    top: 30px;
}

So, the best option it to move your social icon from “Header Top Sidebar” to “Header Right Sidebar”

Or you have change that position in mobile by adding in the following css in “Appearance => Theme Options => Custom CSS” box:

@media screen and (max-width: 768px) {
    #sidebar-header-top {
        position: relative;
        top: 5px;
    }
}