.columnstwo {
  float: left;
  width: 50%;
  padding: 20px;
}

.columnsthree {
  float: left;
  width: 33.33%;
  padding: 15px;
}

.columnsfour {
  float: left;
  width: 25%;
  padding: 10px;
}

/* Clear floats after the columns */
.row:after {
  content: "";
  display: table;
  clear: both;
}

@media screen and (max-width: 600px) {
  .columnstwo {
    width: 100%;
  }
}

@media screen and (max-width: 600px) {
  .columnsthree {
    width: 100%;
  }
}

@media screen and (max-width: 600px) {
  .columnsfour {
    width: 100%;
  }
}