JSFiddle - React, Tailwind, and code Playground

HTML

<div id="field">
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
   <div class="card-boxes"><div class="cards"></div></div>
 </div>

CSS

#field {
  width: 600px;
  margin: 50px auto;
}
.card-boxes {
  border-radius: 3px;
  float: left;
  height: 100px;
  margin: 3px;
  width: 100px;
}

.cards {
  border-radius: 3px;
  font: 60px bold "Arial";
  height: 90px;
  padding-top: 10px;
  text-align: center;
  width: 100px;
}

JavaScript

var letters   = [ "A", "A", "B", "B", "C", "C", "D", "D", "E", "E", "F", "F", "G", "G", "H", "H", "I", "I", "J", "J" ],
    cards     = document.getElementsByClassName( "cards" ),
    cardBoxes = document.getElementsByClassName( "card-boxes" );

var i = letters.length, j, temp;
while ( --i ) {
    j = Math.floor( Math.random() * (i - 1) );
    temp = letters[i];
    letters[i] = letters[j];
    letters[j] = temp;
}

for ( var i = cards.length; i--; ) { 
     cards[i].innerHTML = letters.shift();
}