<div class="grid">
  <div>One</div>
  <div>Two</div>
  <div>Three</div>
  <div>Four</div>
</div>

* { box-sizing: border-box; }

body {
  margin: 40px;
  background-color: #fff;
  color: #444;
  font: 1.4em Arial, sans-serif;
}

.grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  grid-auto-rows: 100px;
  grid-gap: 20px;
}

.grid > * {
padding: 10px;
  border: 5px solid rgba(214,129,137,.5);
  border-radius: 5px;
  background-color: rgba(233,78,119,.5);
  color: #fff;
  float: left;  
  width: 23%;
  margin: 0 1%;
}

@supports (display:grid) {
  .grid > * {
    width: auto;
    margin: 0;
  }
}