.container2:after {
    font-family: FontAwesome;
    content: "\f111";
    display: inline-block;
}

至

.container2:after {
    font-family: FontAwesome;
    content: "\f111";
    display: inline;
}

它似乎与任何宽度的工作,我将容器设置并将保持连接到什么foo将是.