<div class="container">
                                                            <p><em>Click the button below to enter the element into fullscreen mode. </em></p>
                                                            <div class="element" id="element"><p>I change color in fullscreen mode!</p></div>
                                                            <br />
                                                            <button onclick="var el = document.getElementById('element'); el.requestFullscreen();">
                                                              Go Full Screen!
                                                            </button>
                                                          </div>

.container {
                                                            margin: 40px auto;
                                                            max-width: 700px;
                                                          }
                                                          
                                                          .element {
                                                            padding: 20px;
                                                            height: 300px;
                                                            width: 100%;
                                                            background-color: skyblue;
                                                            box-sizing: border-box;
                                                          }
                                                          
                                                          .element p {
                                                            text-align: center;
                                                            color: white;
                                                            font-size: 3em;
                                                          }
                                                          
                                                          .element:-ms-fullscreen p {
                                                            visibility: visible;
                                                          }
                                                          
                                                          .element:fullscreen {
                                                            background-color: #e4708a;
                                                            width: 100vw;
                                                            height: 100vh;
                                                          }