title: CSS: Need an element to scale vertically with its neighbor
body: <p><img src="https://i.stack.imgur.com/LYxUE.png" alt="alt text"></p>
  
  <p>Best illustrated with an image, perhaps.</p>
  
  <ol>
  <li>The tall area (b) to the left of the main content-filled element (d) needs to scale along with that content element (d), but still needs that top-left corner piece (a) at its top.</li>
  <li>There also needs to be elements capping off the bottom of both columns as indicated (c, e).</li>
  <li>The entire area cannot exceed 640px in width.</li>
  <li>There will be more than one of these sections within the flow of the document, so they can't be absolutely positioned or whatever.</li>
  <li>The left column (a,b,c) is a fixed width, and the cap pieces (a,c,e) are fixed heights.  The right column can be fixed width, if that makes things simpler.</li>
  </ol>
  
  <p>How do I do this?</p>