.col,
.col * { 
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  -ms-box-sizing: border-box;
  -o-box-sizing: border-box;
  box-sizing: border-box;
}
.col {
  position: relative;
  float: left;
  padding: 0 1em;
}

.clear:before,
.clear:after {
  content: " ";
  display: table;
}
.clear:after {
  clear: both;
}

@media all and (max-width: 480px) {
  body {background: cyan !important}
  .col { 
    width: 100% !important;
    margin: 0 !important;
  }
}
@media all and (min-width: 1216px) {
  body {background: yellow !important}
}