[a45]

<div class="wrap">
  <div class="block">1</div>
  <div class="block">2</div>
  <div class="block">3</div>
  <div class="block">4</div>
</div>

.wrap{
  display: flex;
  justify-content: space-between;
  flex-wrap:wrap
}

.block{
  min-width:150px;
  border:1px solid;
  text-align: center;
}