模态窗口的问题

var num = 15;

var modalBtn = document.querySelector('.open');
var closeBtn = document.querySelector('.close');

var modalContainer = document.querySelector('.modals');
var holdModals = document.createDocumentFragment();

for (var i = 0; i < num; i++) {
  var div = document.createElement('div');
  div.classList.add('modal-drop');
  div.style.top = Math.floor((Math.random() * 100)) + 'vh';
  div.style.left = Math.floor((Math.random() * 100)) + 'vw';
  div.style.transitionDelay = Math.random() + 's';
  holdModals.appendChild(div);
}
console.log();
modalContainer.appendChild(holdModals);

modalBtn.addEventListener('click',function(){
  modalContainer.style.display = 'block';  
  window.setTimeout(function(){
    modalContainer.classList.add('active');
  },0.1);
});

closeBtn.addEventListener('click',function(){
   modalContainer.classList.remove('active');
  
   window.setTimeout(function(){
    modalContainer.style.display = 'none';
  },3000);
});

.card {
  position: relative;
}

.modals {
  color: #fff;
  display: none;
  position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
  
  &.active {    
    .modal-drop {
      transform-origin: 50%;
      transform: scale(1);
    }
    
    .modal-content {
      opacity: 1;
      transition: 0.5s ease-in 1.5s;
    }
  }
}

.modal-drop {
  background: hsl(250,30%,10%);
  border-radius: 50%;
  width: 150vh;
  height: 150vh;
  position: absolute;
  margin-left: -75vh;
  margin-top: -75vh;
  transition: transform 2s cubic-bezier(.25,1,.60,1), transform-origin 0s;
  transform: scale(0.001);
  transform-origin: 0 0;
}

.modal-content {
  background: hsl(250,30%,10%);
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  opacity: 0;
  z-index: 1;
  transition: 0.5s 0s;
  
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-wrap {
  flex: 1;
  width: 100%;
  max-width: 50em;  
}

/* Page Styling */

$font-size: 18/16*1em;

::selection {
  background: hsl(40,100%,65%);
  color: #fff;
}

::-moz-selection {
  background: hsl(40,100%,65%);
  color: #fff;
}

html, body {
  height: 100%;
}

body {
  background: hsl(30,10%,90%);
  color: hsl(200,50%,20%);
  font: #{$font-size}/1.65 'Open Sans', sans-serif;
  letter-spacing: 0.01em;
  text-rendering: optimizeLegibility;
  
  display: flex;
  align-items: center;
  justify-content: center;
}

.card {
  background: #fff;
  flex: 1;
  max-width: 20em;
  padding: 3em;
  position: relative;
  width: 100%;
  
  &::before {
    content: '';
    border: 1px dotted hsl(165,80%,70%);
    position: absolute;
      top: 1.25em;
      right: 1.25em;
      bottom: 1.25em;
      left: 1.25em;
    pointer-events: none;
  }
  
  p {
    margin: 0.5em 0 1em;
    padding-bottom: 2em;
    border-bottom: 1px solid hsl(149,70%,90%);
    //text-align: center;
    //font-style: italic;
    //font-family: 'Playfair Display', serif;
  }
}

.open,
.close {
  background: linear-gradient(hsl(149,65%,74%),hsl(155,67%,68%));
  border: 1px solid hsl(155,67%,68%);
  border-bottom: 4px solid hsl(165,70%,55%);
  border-radius: 2px;
  color: #fff;
  font-weight: 600;
  margin-top: 0.5em;
  padding: 0.5em 1em 0.4em;
  text-shadow: 1px 1px 0 hsl(165,70%,55%);
  transition: 0.3s;
  
  &:hover {
    filter: brightness(90%) contrast(120%);
  }
  
  &:focus {
    box-shadow: 0 0 10px hsl(149,65%,74%);
    outline: none;
  }
  
  float: right;
}

.close {
  background: linear-gradient(hsl(10,95%,59%),hsl(360,95%,59%));
  border: 1px solid hsl(360,95%,59%);
  border-bottom: 4px solid hsl(360,95%,43%);
  text-shadow: 1px 1px 0 hsl(360,95%,43%);
  
  &:focus {
    box-shadow: 0 0 10px hsl(10,95%,59%);
  }
}

<div class="card">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Incidunt deserunt velit in blanditiis, cupiditate possimus sapiente tenetur porro accusantium animi?</p>
  
  <button class="open">Modal</button>
</div>

<div class="modals">
  <div class="modal-content">
    <div class="modal-wrap">
      <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Inventore ab officiis libero reiciendis voluptas hic quas sit aspernatur exercitationem numquam obcaecati dolore sed voluptates, at aliquam cum harum, necessitatibus, expedita quod et magni? Possimus maiores vero suscipit ipsum veritatis, omnis pariatur magnam voluptatibus quisquam sequi veniam quas, et, dignissimos perspiciatis.</p>
      <button class="close">Close</button>
    </div>
  </div>
</div>