It is better to use snack bars or pop-ups to display short messages to the user. In this code, both of these are merged and the pop-up is displayed along with the snack bar. Clicking on the button on the screen will display the snack bar and it will be deleted automatically after a few seconds. In Van Snack Bar can be any small message. The background of the snack bar is black, albeit with a bit of transparency.


HTML
<!-- This script got from www.devanswer.com  -->
<div class="container">
  <h2>Snackbar Popup</h2>
  <p>Click on the button to show the snackbar. It will disappear after 3 seconds.</p>
  <button onclick="myFunction()">Show Snackbar</button>
  <div id="snackbar">Some text some message..</div>
</div><div id="bcl"><a style="font-size:8pt;text-decoration:none;" href="http://www.devanswer.com ">Developers Answer</a></div>
                        

CSS
#snackbar {
  visibility: hidden;
  min-width: 250px;
  margin-left: -125px;
  background-color: #333;
  color: #fff;
  text-align: center;
  border-radius: 2px;
  padding: 16px;
  position: fixed;
  z-index: 1;
  left: 50%;
  bottom: 30px;
  font-size: 17px;
}
#snackbar.show {
  visibility: visible;
  -webkit-animation: fadein 0.5s, fadeout 0.5s 2.5s;
  animation: fadein 0.5s, fadeout 0.5s 2.5s;
}
@-webkit-keyframes fadein {
  from {bottom: 0; opacity: 0;} 
  to {bottom: 30px; opacity: 1;}
}
@keyframes fadein {
  from {bottom: 0; opacity: 0;}
  to {bottom: 30px; opacity: 1;}
}
@-webkit-keyframes fadeout {
  from {bottom: 30px; opacity: 1;} 
  to {bottom: 0; opacity: 0;}
}
@keyframes fadeout {
  from {bottom: 30px; opacity: 1;}
  to {bottom: 0; opacity: 0;}
}
.container {
  width: 90%;
  max-width: 100%;
  padding: 15px;
  margin: 0 auto;
}
button {
  width: 131px;
  height: 45px;
  background: greenyellow;
  border-radius: 5px;
  cursor: pointer;
}
Javascript
function myFunction() {
  var x = document.getElementById("snackbar");
  x.className = "show";
  setTimeout(function(){ x.className = x.className.replace("show", ""); }, 3000);
}