[html] Overlay with spinner

Here is simple overlay div without using any gif, This can be applied over another div.

<style>
.loader {
  position: relative;
  border: 16px solid #f3f3f3;
  border-radius: 50%;
  border-top: 16px solid #3498db;
  width: 70px;
  height: 70px;
  left:50%;
  top:50%;
  -webkit-animation: spin 2s linear infinite; /* Safari */
  animation: spin 2s linear infinite;
}
#overlay{
    position: absolute;
    top:0px;
    left:0px;
    width: 100%;
    height: 100%;
    background: black;
    opacity: .5;
}
.container{
    position:relative;
    height: 300px;
    width: 200px;
    border:1px solid
}

/* Safari */
@-webkit-keyframes spin {
  0% { -webkit-transform: rotate(0deg); }
  100% { -webkit-transform: rotate(360deg); }
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}
</style>

<h2>How To Create A Loader</h2>

<div class="container">
  <h3>Overlay over this div</h3>
  <div id="overlay">
      <div class="loader"></div>
  </div>
<div>