Modals are built with HTML, CSS, and JavaScript. They’re positioned over everything else in the document and remove scroll from the so that modal content scrolls instead.
<!-- Button trigger modal --> <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModalCenter"> Launch demo modal </button> <!-- Modal --> <div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true"> <div class="modal-dialog modal-dialog-centered" role="document"> <div class="modal-content"> <div class="modal-header"> <h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5> <button type="button" class="close" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">×</span> </button> </div> <div class="modal-body"> ... </div> <div class="modal-footer"> <button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button> <button type="button" class="btn btn-primary">Save changes</button> </div> </div> </div> </div>
<!-- Extra large modal --> <button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bd-example-modal-xl">Extra large modal</button> <div class="modal fade bd-example-modal-xl" tabindex="-1" role="dialog" aria-labelledby="myExtraLargeModalLabel" aria-hidden="true"> <div class="modal-dialog modal-xl"> <div class="modal-content"> ... </div> </div> </div> <!-- Large modal --> <button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bd-example-modal-lg">Large modal</button> <div class="modal fade bd-example-modal-lg" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel" aria-hidden="true"> <div class="modal-dialog modal-lg"> <div class="modal-content"> ... </div> </div> </div> <!-- Small modal --> <button type="button" class="btn btn-primary" data-toggle="modal" data-target=".bd-example-modal-sm">Small modal</button> <div class="modal fade bd-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel" aria-hidden="true"> <div class="modal-dialog modal-sm"> <div class="modal-content"> ... </div> </div> </div>