SOURCE

 <div class="grid-test">
      <div class="box-test">1</div>
      <div class="box-test">2</div>
      <div class="box-test">3</div>
      <div class="box-test">4</div>
      <div class="box-test">5</div>
      <div class="box-test">6</div>
      <div class="box-test">7</div>
      <div class="box-test">8</div>
      <div class="box-test">1</div>
      <div class="box-test">2</div>
      <div class="box-test">3</div>
      <div class="box-test">4</div>
      <div class="box-test">5</div>
      <div class="box-test">6</div>
      <div class="box-test">7</div>
      <div class="box-test">8</div>
    </div>

.grid-test {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 10px;
  background: blue

}

.box-test {
  height: 100px;
  background: red;
  margin: 10px;
}