.fl {
    float: left;
}

.fr {
    float: right;
}

.fn {
    float: none;
}

.clr {
    clear: both;
    height: 0;
    font-size: 0;
    line-height: 0;
    overflow: hidden;
}

.clear {
    clear: both;
}

.gray {
    color: gray;
}