title: Child element 100% width of it's parent with overflow: scroll
body: <p>I'm searching for a solution to get the child element 100% width of it's parent.</p>
  
  <p>The problem: The parent has <code>overflow-x: scroll</code>. Text will insert a scrollbar. Now I want a child to get (the new) width of it's container.</p>
  
  <p>Requirements: Pure CSS solution; no further HTML markup; no fixed width.</p>
  
  <p><code>width: 100%</code> will set it only to the init state width of the container.</p>
  
  <p>Here is a fiddle: <a href="https://jsfiddle.net/y166e3nb/" rel="noreferrer">https://jsfiddle.net/y166e3nb/</a></p>