title: How to make a Elastic Vertical Layout?
body: <p>I have a page that has 2 areas: header and content.<br>
  The header should be [of course] fixed at the top, and has no fixed height, and the content below it.</p>
  
  <p>The point is that I need my content area to be scrolled if it overflows... Like: the header should be always there, but the content can be scrolled down, i.e. your browser window, with the bars always at the top and the page scrolling.</p>
  
  <p>I'm using JS to do this in a different page, where the "footer" has a fixed height, so I could say "hey, content, use the page height minus the footer height".</p>
  
  <p>Can I implement this with only HTML+CSS, or do I need to use JS? And how?</p>