Build a Technical Documentation Page

The first child of each .main-section should be a header element.

It’d be better if you provided more information like, your HTML & CSS so we can better understand what exactly the issue is.

Either way, " The first child of each .main-section should be a header element. " means that you code should look something like this:

<section class="main-section">
  <header></header>

  <!-- Other content... -->
</section>