JSFiddle - React, Tailwind, and code Playground

HTML

<b class="shadow grad pulsate">#1</b>

CSS

.grad{
    color: #0a77d5; /* Old browsers */
    color: -moz-linear-gradient(top, #d0e4f7 0%, #73b1e7 24%, #0a77d5 50%, #539fe1 79%, #87bcea 100%); /* FF3.6-15 */
    color: -webkit-linear-gradient(top, #d0e4f7 0%,#73b1e7 24%,#0a77d5 50%,#539fe1 79%,#87bcea 100%); /* Chrome10-25,Safari5.1-6 */
    color: linear-gradient(to bottom, #d0e4f7 0%,#73b1e7 24%,#0a77d5 50%,#539fe1 79%,#87bcea 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */

   }


   .pulsate {
     -webkit-animation: pulsate 1.5s ease-out;
     -webkit-animation-iteration-count: infinite;
     animation: pulsate 1.5s ease-out;
     animation-iteration-count: infinite;
     opacity: 1.0;
     transform: scale(1);
     display:inline-block;
 }
 @-webkit-keyframes pulsate {
     0% {
         opacity: 0.5;
         -webkit-transform: scale(1.0);
         transform: scale(1.0);
     }
     50% {
         opacity: 1.0;
         -webkit-transform: scale(2.0);
         transform: scale(2.0);
     }
     100% {
         opacity: 0.5;
         -webkit-transform: scale(3.0);
         transform: scale(3.0);
     }
   }

**.shadow {
    text-shadow: 0 1px 0 #ccc,
      0 2px 0 #c9c9c9,
      0 3px 0 #bbb,
      0 4px 0 #b9b9b9,
      0 5px 0 #aaa,
      0 6px 1px rgba(0, 0, 0, .1),
      0 0 5px rgba(0, 0, 0, .1),
      0 1px 3px rgba(0, 0, 0, .3),
      0 3px 5px rgba(0, 0, 0, .2),
      0 5px 10px rgba(0, 0, 0, .25),
      0 10px 10px rgba(0, 0, 0, .2),
      0 20px 20px rgba(0, 0, 0, .15);
    box-shadow: none !important;

  }

JavaScript

document.getElementById('toggle').addEventListener('click', function(e){
	let source = e.currentTarget
  source.disabled = true
	let popin = document.getElementById('popin')
  
  if (popin.classList.contains('hidden')){
    popin.classList.remove('hidden')
    setTimeout(() => {
      popin.classList.remove('closed')
    }, 3)
  }
  else{
  	popin.classList.add('closed')
    setTimeout(() => {
      popin.classList.add('hidden')
    }, 810)
  }
  
  setTimeout(() => {
  	source.disabled = false
  }, 850)
})