.col {
  float: left;
  box-sizing: border-box;
}

[class*='col-'] {
  padding-right: 20px;
}

[class*='col-']:last-of-type {
  padding-right: 0;
}

.col-2-3 {
  width: 66.6666%;
}

.col-1-2 {
  width: 50%;
}

.col-1-3 {
  width: 33.3333%;
}

.col-1-4 {
  width: 25%;
}

.col-1-8 {
  width: 12.5%;
}

.cf:after {
  content: '';
  display: block;
  clear: both;
}

@media all and (max-width: 900px) {
  [class*='col-'] {
    width: 100%;
  }
}