.one-half, .one-third, .one-fourth, .two-thirds, .three-fourths, .full-width { display: inline-block; float: left; margin-right: .5%; }

.one-half { width: 49.5%; }
.one-third { width: 33%; }
.one-fourth { width: 24.5%; }
.two-thirds { width: 64%; }
.three-fourths { width: 70.5%; padding-right: 4%; }
.full-width { width: 99.5%; }
.column-last { margin-right: 0!important; }

@media only screen 
and (min-width : 320px) 
and (max-width : 767px) {

.one-half, .one-third, .one-fourth, .two-thirds, .three-fourths { margin: .5% 0; }

.one-half { width: 100%; }
.one-third { width: 100%; }
.one-fourth { width: 100%; }
.two-thirds { width: 100%; }
.three-fourths { width: 100%; padding-right: 0; }
.full-width { width: 100%;}
.column-last { margin-right: 0 !important; }

}