<div>
  .9rem
  <div>
    .9rem
    <div>
      .9rem
      <div>
        .9rem
      </div>
    </div>
  </div>
</div>

HTML {
  font-size: 24px;
}

DIV {
  font-size: .9rem;
  
  // Helpers
  padding: .25rem .5rem;
  line-height: 1.3;
  text-align: center;
  outline: 1px solid #DDD;
  
  & > & {
    margin-top: .25rem;
  }
}

// Helpers
BODY {
  background: white;
  min-height: 100vh;
  display: grid;
  grid-template-columns: repeat(2, min-content);
  align-items: center;
  align-content: center;
  justify-content: center;
  gap: 1rem;
  font-family: Arial, sans-serif;
  font-size: 10rem;
}