.premium-col-left {
  max-width: 100%;
}

.premium-col-right {
  max-width: 100%;
}

@media only screen and (min-width : 640px) {

  .premium-col-left {
    float: left;
    width: 45%;
  }

  .premium-col-right {
    float: right;
    width: 45%;
  }
}