Simple and responsive image slider regardless of viewport etc.

All you need to do is copy and paste the code from start to finish like so:

<div class="slide-image">
  <div class="title">
    <h1>Title</h1>
    <p>Undertitle</p>
  </div>
  <div class="overlay"></div>
  <img src="img.jpg" alt="" />
</div>

It will update everything automatically, so you don't need to touch the CSS or Javascript.