JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="box blue">Blue</div>
  <div class="box blue">Blue</div>
  <div class="box orange">Orange</div>
  <div class="box green">Green</div>
  <div class="box green">Green</div>
  <div class="box green">Green</div>
  <div class="box red">Red</div>
  <div class="box red">Red</div>
  <div class="box red hide-reds">Red</div>
  <div class="box red hide-reds">Red</div>
</div>

CSS

.container {
  display: flex;
  flex-wrap: wrap;
}

.box {
  flex: 0 0 100%;
}

.red {
  flex: 1 0 100%;
  background: red;
  height: 170px;
}

.hide-reds {
  display: none;
}

@media all and (min-width: 800px) {
  .red {
    flex-basis: 40%; /* see note below */
    display: block;
  }
}


/* not relevant to the question */

.blue {
  background: blue;
}

.orange {
  background: Orange;
  height: 300px;
}

.green {
  background: green;
}

html {
  font-size: 20px;
}

.box {
  color: white;
  font-size: 100px;
  text-align: center;
  text-shadow: 4px 4px 0 rgba(0, 0, 0, 0.1);
  padding: 10px;
  margin: 5px;
}