JSFiddle - React, Tailwind, and code Playground

HTML

<button class="myBtn" data-modal="myModal1" >Open Modal</button>
<div id="myModal1" class="modal">
  <div class="modal-content">
    <div class="modal-header">
      <span class="close" data-modal="myModal1">&times;</span>
     
    </div>
    <div class="modal-body">
       text
    </div>
  </div>
</div>

CSS

.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 100000; /* Sit on top */
    padding-top: 172px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}

/* Modal Content */
.modal-content {
    position: relative;
    /* background-color: #fefefe; */
    margin: auto;
    padding: 0;
    /* border: 1px solid #888; */
    width: 684px;
    box-shadow: 0 4px 8px 0 rgba(0,0,0,0.2),0 6px 20px 0 rgba(0,0,0,0.19);
    -webkit-animation-name: animatetop;
    -webkit-animation-duration: 0.4s;
    animation-name: animatetop;
    animation-duration: 0.4s;
}

/* Add Animation */
@-webkit-keyframes animatetop {
    from {top:-300px; opacity:0} 
    to {top:0; opacity:1}
}

@keyframes animatetop {
    from {top:-300px; opacity:0}
    to {top:0; opacity:1}
}

/* The Close Button */
.close {
    margin-top: -11px;
    color: white;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close:hover,
.close:focus {
    color: #000;
    text-decoration: none;
    cursor: pointer;
}

JavaScript

var modal = document.getElementById('myModal');
var buttons = document.getElementsByClassName("myBtn")
var span = document.getElementsByClassName("close");

for (var i = 0; i < buttons.length; i++) {
	buttons[i].onclick = function() {
    var id = this.getAttribute('data-modal');
    var modal = document.getElementById(id);
    modal.style.display = 'block';
  }
}

for (var i = 0; i < span.length; i++) {
  span[i].onclick = function() {
    var id = this.getAttribute('data-modal');
    var modal = document.getElementById(id);
    modal.style.display = 'none';
  }
}

window.onclick = function(event) {
  var isModal = (' ' + event.target.className + ' ').indexOf(' modal ') > -1;
  if (isModal) {
    event.target.style.display = "none";
  }
}