title: How do I detect browsers on mobile or on desktop?
body: <p>When I presume that a css media query with <code>max-width: 768px</code> can make my web page responsive to fit a mobile device. However, iPhone X and later still load the desktop version, because recent phones have even higher resolution than an old desktop.</p>
  <p>How do I detect a mobile device not relying on the screen resolution, with Vanilla javascript, pure HTML and CSS?</p>