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                <h1>With Vanilla JavaScript</h1>
<div class="toggle">
  <button>Toggle SlideIn</button>

<!-- Slide In box will be hidden until toggled open -->
<div class="slidein">
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Incidunt cum, harum, quaerat porro, maiores facilis molestias illum impedit quo repellat enim provident perspiciatis molestiae in saepe id cupiditate eveniet asperiores.</p>
  <button class="close-btn"> X </button>


                /* Make slide in box hidden off screen with fixed positioning 100% to the right */
.slidein {
  max-width: 600px;
  padding: 2em 3em; 
  position: fixed; 
  z-index: 100;
  top: 0;
  right: -100%;
  background: #ddd;
  height: 100%;
  box-shadow: 1px 1px 10px rgba(0,0,0,.5);
  transition: all .5s ease-in-out; 

/* Set positioning back to 0 when toggled opened */
.open {
  right: 0; 

/* add a close button in case toggle button is hidden on smaller screens */
.close-btn {
  border: none; 
  font-weight: bold; 
  font-size: 2em; 
  background: transparent; 
  position: absolute; 
  top: 0;
  left: 0;
  padding: .5em;

/* General styles unrelated to slide in */
body {
  font-family: 'Mulish', sans-serif;

.toggle {
  margin: 1em;

button {
  padding: .5em 1em;
  border-radius: 3em;
  font-size: 1.1em;

h1 {
  font-weight: 200;


                /* Code to toggle the slide in box state to open or closed. Opened state has 'open' class */

let btn = document.querySelector('button');
let slidein = document.querySelector('.slidein');
let closeBtn = document.querySelector('.close-btn');

btn.addEventListener('click', function() {
closeBtn.addEventListener('click', function() {