JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="child">
    test content
  </div>
  <div class="child">
    test content
  </div>
  <div class="child">
    test content
  </div>
</div>

CSS

.container{
  display: flex;
  flex-flow: row wrap;
  justify-content: space-between;
  margin-right: -10px;
}

.child{
  flex-grow: 1;
  max-width: 450px;
  min-width: 350px;
  margin-top: 10px;
  margin-right: 10px;
  background: blue;
  height: 400px;
}

.container::after {
    content: "";
      flex-grow: 1;
  max-width: 450px;
  min-width: 350px;
}