.section {
    position  : relative;
    height    : 100%;
    width     : 100%;
    text-align: center;
}

.section_submit {
    position: absolute;
    bottom  : 0px;
    width   : 100%;
    margin  : 48px 0px;
    -webkit-transition: opacity .3s;
       -moz-transition: opacity .3s;
        -ms-transition: opacity .3s;
         -o-transition: opacity .3s;
            transition: opacity .3s;
}