SOURCE

<div class="wrapper">
    <div class="inner-box">1</div>
    <div class="inner-box">2</div>
    <div class="inner-box">3</div>
    <div class="inner-box">4</div>
    <div class="inner-box">5</div>
    <div class="inner-box">6</div>
</div>

.wrapper {
  display: grid;
  grid-template-columns: 50% 30px 80px;
  grid-template-rows: 40px 100px 100px;
}
.inner-box{
  background:pink;
}