JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.1.0.min.js"   
		integrity="sha256-cCueBR6CsyA4/9szpPfrX3s49M9vUU5BgtiJj06wt/s=" 
		crossorigin="anonymous">
	</script>
<body id="game">

	</body>

JavaScript

// A 10x10 grid implemented with Javascript Array 
		var rows=7; 
		var cols = 6; 
		var grid = []; 

		var validFigures=0;
		var levelGoal = 0;


		 // game object 
 		function jewel(r,c,obj,src)
	    	{
			return {
				r: r,
				c: c,
				src:src,
				locked:false,
				isInCombo:false,
				o:obj
			}
		}

  // Jewels used in Solar System JSaga
             var jewelsType=[];
     
         
             jewelsType[0]="https://upload.wikimedia.org/wikipedia/commons/d/d8/OpenEmulator.png";
             jewelsType[1]="http://beachfrontreach.com/wp-content/uploads/2015/08/html5-icon.png";
     
             jewelsType[2]="https://upload.wikimedia.org/wikipedia/commons/8/8d/DVD_video_icon.png"; 
             jewelsType[3]="https://upload.wikimedia.org/wikipedia/commons/1/16/Glossy_3d_blue_plussign.png";
             jewelsType[4]="https://upload.wikimedia.org/wikipedia/commons/thumb/0/02/Tumblr-2.svg/256px-Tumblr-2.svg.png";
             jewelsType[5]="https://upload.wikimedia.org/wikipedia/en/thumb/f/f0/Information_orange.svg/256px-Information_orange.svg.png";
             jewelsType[6]="https://upload.wikimedia.org/wikipedia/commons/d/d7/The_KMPlayer_icon_%28since_v3.2%29.png";
             
             // this function returs a random jewel.
             function pickRandomJewel()
             
              {
                 var pickInt = Math.floor((Math.random()*7));
                 //console.log("Picked " + pickInt);
                 return jewelsType[pickInt];
             }


	    function _initGame() { 

		 // prepare grid - Simply and fun!
		 for (var r = 0; r < rows; r++)
		   {
		      grid[r]=[];
		       for (var c =0; c< cols; c++) {
		         grid[r][c]=new jewel(r,c,null,pickRandomJewel());
		     }
		  }    
 				_applyRectangleConstraint(1,1,1,1);
	

			// initial coordinates
		 	var width = $('body').width();
		 	var height = $(document).height();

			console.log("Game width: " + width);
			console.log("Game height: " + height);
	
...