<!DOCTYPE html>
<style>
body {
  font-size: 20px;
  font-family: ahem;
}
.container {
  border: 10px solid blue;
  width: 600px;
}
</style>
<div class=container>
  <span style="background-color: red">flex items</span><span style="background-color: white;">flex items</span><span style="background-color: green">everywhere</span>
</div>