equal size columns css code example

Example 1: same height div css

################ HTML ########################
<div class="row">
  <div class="col">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</div>
  <div class="col">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam.</div>
  <div class="col">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo.</div>
</div>

################# CSS ########################
.row {
  display: grid;
  grid-auto-flow: column;
  grid-gap: 5%;
}

.col {
  border: solid;
}

Example 2: make three column with equal height using flexbox

.pseudo-three-col {
  position: relative;
  background: #eee;
  z-index: 1;
  width: 100%;
}
.pseudo-three-col .col {
  position: relative;
  width: 27%;
  padding: 3%;
  float: left;
}
.pseudo-three-col .col:nth-child(1) { left: 33%; border:solid black }
.pseudo-three-col .col:nth-child(2) { left: -33.3%; }
.pseudo-three-col .col:nth-child(3) { left: 0; }
.pseudo-three-col:before, .pseudo-three-col:after {
  content: " ";
  position: absolute;
  z-index: -1;
  top: 0;
  left: 33.4%;
  width: 33.4%;
  height: 100%;
  background: #ccc;
}
.pseudo-three-col:after {
  left: 66.667%;
  background: #eee;
}