​<script type="text/javascript" src="https://code.jquery.com/jquery-1.8.2.js"></script>
<style type="text/css">
#overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #000;
    filter:alpha(opacity=70);
    -moz-opacity:0.7;
    -khtml-opacity: 0.7;
    opacity: 0.7;
    z-index: 100;
    display: none;
}

.popup a{
    text-decoration: none;
    font-weight: 700;
   font-size: 25px;
   position: absolute;
   top: 0;
   right: 0;
   padding: 10px 20px;
   color: #aa0722!important;
}

.pop_container{
    width: 100%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    position: fixed;
    z-index: 101;
}

.popup{
    width: auto !important;
    min-height: 150px;
    margin: 50px auto;
    background: #fff;
    position: relative;
    z-index: 103;
    padding: 16px;
    border-radius: 5px;
    box-shadow: 0 2px 5px #000;
    text-align: center;
}

.popup a img{
    width: 100%;
    padding-top: 35px;
}

@media (max-width:480px){
    .popup {
    width: auto !important;
   min-height: 30vh !important;
   height: 60vh !important;
   padding: 22px;
    }
}

.popup p{
clear: both;
   color: #555555;
   / text-align: justify; /
   font-size: 20px;
   font-family: sans-serif;
}
.popup p a{
    color: @primary;
    font-weight: bold;
}
.popup .x{
    float: right;
    height: 35px;
    left: 22px;
    position: relative;
    top: -25px;
    width: 34px;
}

.popup .x:hover{
    cursor: pointer;
}
</style>

<script type='text/javascript'>
$(function(){
var overlay = $('<div id="overlay"></div>');
overlay.show();
overlay.appendTo(document.body);
$('.pop_container').show();
$('.close').click(function(){
$('.pop_container').hide();
overlay.appendTo(document.body).remove();
return false;
});

$('.x').click(function(){
$('.pop_container').hide();
overlay.appendTo(document.body).remove();
return false;
});
});
</script>

<div class='pop_container'>
<div class='popup'>
<!-- Insert Content Below --> 
<iframe style="height:373px; width:300px; border:medium none; " src="https://www.flipcause.com/embed/html_widget/NzA1MTk=" scrolling="no"></iframe>
<!-- end of content -->
<a href='' class='close'>✕</a>
</div>
</div>


==========

<script type="text/javascript" src="https://code.jquery.com/jquery-1.8.2.js"></script> 
<style type="text/css"> 
#overlay { 
position: fixed; 
top: 0; 
left: 0; 
width: 100%; 
height: 100%; 
background-color: #000; 
filter:alpha(opacity=70); 
-moz-opacity:0.7; 
-khtml-opacity: 0.7; 
opacity: 0.7; 
z-index: 100; 
display: none; 
} 
.cnt223 a{ 
text-decoration: none; 
} 
.popup{ 
width: 100%; 
margin: 0 auto; 
display: none; 
position: fixed; 
z-index: 101; 
} 
.cnt223{ 
max-width: 400px; 
min-height: 150px; 
margin: 50px auto; 
background: #ffffff; 
position: relative; 
z-index: 103; 
padding: 15px 35px; 
border-radius: 5px; 
box-shadow: 0 2px 5px #000; 
} 
.cnt223 p{ 
clear: both; 
color: #555555; 
/* text-align: justify; */ 
font-size: 20px; 
font-family: sans-serif; 
} 
.cnt223 p a{ 
color: #d91900; 
font-weight: bold; 
} 
.cnt223 .x{ 
height: 35px; 
left: 22px; 
position: relative; 
top: -25px; 
width: 34px; 
} 
.cnt223 .x:hover{ 
cursor: pointer; 
} 
.close { 
color: gray !important; 
} 
</style> 
<script type='text/javascript'> 
$(function(){ 
var overlay = $('<div id="overlay"></div>'); 
overlay.show(); 
overlay.appendTo(document.body); 
$('.popup').show(); 
$('.close').click(function(){ 
$('.popup').hide(); 
overlay.appendTo(document.body).remove(); 
return false; 
}); 




$('.x').click(function(){ 
$('.popup').hide(); 
overlay.appendTo(document.body).remove(); 
return false; 
}); 
}); 
</script> 
<div class='popup'> 
<div class='cnt223'> 
<a href='' class='close'><b>Close</b></a> 
<center>
<iframe style="height:373px; width:300px; border:medium none; " src="https://www.flipcause.com/embed/html_widget/NzA3MDI=" scrolling="no">
</iframe></center> 
<br/> 
<br/> 
</p> 
</div> 
</div>