body {    
}

.icon_btn {
    width: 48px;
    height: 48px;
    border: none;
}

.icon_btn_hoverable {
    opacity: 0.7;
}

    .icon_btn_hoverable:hover {
        opacity: 1;
    }

.vk_btn {
    background: url(/images/system/icons.png) -49px 0;
}

.fb_btn {
    background: url(/images/system/icons.png) 0 0;
}