title: Making navbar collapse with JS
body: <p>Currently my navbar shrinks with the page size, using <code>@media screen</code>. This works fine, but when the page is very small I want the navbar to collapse into a vertical drop down which requires a click to open. </p>
  
  <p>Due to my circumstances I cannot use bootstrap, just html/css and js. </p>
  
  <p>example on <a href="https://jsfiddle.net/Senzai/6vom6bq6/1/" rel="nofollow noreferrer">jsfiddle</a></p>