Why does my "Popup window" not showing for the second time on click?

Question

I have above code work fine here ( if i run code ) but it causing me error on my website. What's happening is that on first time click on all links works fine but when i try to click second time then it shows blank page and you can't click anywhere on page so either i have to refresh or click back button.

.overlay {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
  transition: opacity 500ms;
  visibility: hidden;
  opacity: 0;
    overflow:hidden;
  z-index:9999999;
}
.overlay:target {
  visibility: visible;
  opacity: 1;
}

.popup {
  margin: 70px auto;
  padding: 20px;
  background: #fff;
  border-radius: 5px;
  width: 30%;
  position: relative;
  transition: all 5s ease-in-out;

}

.popup h2 {
  margin-top: 0;
  color: #333;
  font-family: Tahoma, Arial, sans-serif;
}
.popup .close {
  position: absolute;
  top: 20px;
  right: 30px;
  transition: all 200ms;
  font-size: 30px;
  font-weight: bold;
  text-decoration: none;
  color: #000;
}
.popup .close:hover {
  color: #06D85F;
}
.popup .content {
  max-height: 30%;
  overflow: auto;
}

@media screen and (max-width: 700px){

  .popup{
    width: 70%;
  }
}

<div style="clear:both; height:23px; font-size:9px; color:#0033FF; text-align:right; margin-right:11px;"><a href="#1" >View</a></div>
                          <div id="1" class="overlay">
	<div class="popup">
		<h2>pop up window one </h2>
		<a class="close" href="#" >&times;</a>
		<div class="content">
			this is my pop up window 1
		</div>
	</div>
</div>


<div style="clear:both; height:23px; font-size:9px; color:#0033FF; text-align:right; margin-right:11px;"><a href="#2" >View</a></div>
                          <div id="2" class="overlay">
	<div class="popup">
		<h2>pop up window one </h2>
		<a class="close" href="#" >&times;</a>
		<div class="content">
			this is my pop up window 1
		</div>
	</div>
</div>



<div style="clear:both; height:23px; font-size:9px; color:#0033FF; text-align:right; margin-right:11px;"><a href="#3" >View 3</a></div>
                          <div id="3" class="overlay">
	<div class="popup">
		<h2>pop up window one </h2>
		<a class="close" href="#" >&times;</a>
		<div class="content">
			this is my pop up window 1
		</div>
	</div>
</div>

Answer 1

As per your instructions I got that there is a problem with theme.js file in your website.

whenever you are clicking that close "x" button of popup a function in that file at line number 105 triggers and adds a inline css in your popup and reduces the opacity of the popup div to "opacity:0".

solution: you can just change that class name and remove the click even as a temporary solution. or you can edit theme.js file and reduce your code and get better performance...

choice is yours I hope that this will help you. or else you can tell me for any kind of help! Thank you!

Happy Coding!!!