Usually we need modals and pop-ups on the website for different things. This code uses a pop-up. This pop-up is provided to remove something from the website. Suppose you have a table and you want to delete a row from it. It is best to be warned beforehand to make sure the deletion operation is complete. In this code, this warning is done with the help of a pop-up. This pop-up is full width and its background color is white.


HTML
<!-- This script got from www.devanswer.com -->
<link rel="stylesheet" href="https://netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<div class="container-fl">
  <h2>Delete Modal</h2>
  <button onclick="document.getElementById('id01').style.display='block'">Open Modal</button>
  <div id="id01" class="modal">
    <span onclick="document.getElementById('id01').style.display='none'" class="close" title="Close Modal">×</span>
    <form class="modal-content" action="/action_page.php">
      <div class="container">
        <h1>Delete Account</h1>
        <p>Are you sure you want to delete your account?</p>
        <div class="clearfix">
          <button type="button" onclick="document.getElementById('id01').style.display='none'" class="cancelbtn">Cancel</button>
          <button type="button" onclick="document.getElementById('id01').style.display='none'" class="deletebtn">Delete</button>
        </div>
      </div>
    </form>
  </div>
</div><div id="bcl"><a style="font-size:8pt;text-decoration:none;" href="http://www.devanswer.com">Developers Answer</a></div>
                        

CSS
body {font-family: Arial, Helvetica, sans-serif;}
* {box-sizing: border-box;}
button {
  background-color: #04AA6D;
  color: white;
  padding: 14px 20px;
  margin: 8px 0;
  border: none;
  cursor: pointer;
  width: 100%;
  opacity: 0.9;
}
button:hover {
  opacity:1;
}
.cancelbtn, .deletebtn {
  float: left;
  width: 50%;
}
.cancelbtn {
  background-color: #ccc;
  color: black;
}
.deletebtn {
  background-color: #f44336;
}
.container {
  max-width: 100%;
  padding: 16px;
  text-align: center;
}
.container-fl {
  margin: 0 auto;
  width: 90%;
}
.modal {
  display: none; 
  position: fixed; 
  z-index: 1; 
  left: 0;
  top: 0;
  width: 100%; 
  height: 100%; 
  overflow: auto;
  background-color: #474e5d;
  padding-top: 50px;
}
.modal-content {
  background-color: #fefefe;
  margin: 5% auto 15% auto; 
  border: 1px solid #888;
  width: 80%; 
}
hr {
  border: 1px solid #f1f1f1;
  margin-bottom: 25px;
}
.close {
  position: absolute;
  right: 35px;
  top: 15px;
  font-size: 40px;
  font-weight: bold;
  color: #f1f1f1;
}
.close:hover,
.close:focus {
  color: #f44336;
  cursor: pointer;
}
.clearfix::after {
  content: "";
  clear: both;
  display: table;
}
@media screen and (max-width: 300px) {
  .cancelbtn, .deletebtn {
     width: 100%;
  }
}
Javascript
var modal = document.getElementById('id01');
window.onclick = function(event) {
  if (event.target == modal) {
    modal.style.display = "none";
  }
}