.clearfix:after{
    content:".";
    display:block;
    height:0;
    font-size: 0;
    clear:both;
    visibility:hidden
}
.clearfix{*+height:1%;}
.fl{
    float: left;
}
.fr{
    float: right;
}
.headerHeight{
    height:44px;
}
.tac{
    text-align: center;
}
.tar{
    text-align: right;
}
html{
    width: 100%;
    overflow-x: hidden;
}