Frame by frame sinusoidal animation

HTML

<div class = "changer-container">
	Pulsing Page
</div>

CSS

.changer-container {
	margin: 0 auto;
	width: 900px;
	height: 900px;
	background-color: #E8E8E8;
}

JavaScript

$(document).ready(function(e){
      var j = 0;
      var i = 10;
      var fontsize;
      var mark = new Boolean(true); 
      function pulseLoop() {
			fontsize = (Math.sin(i) * 10) + 50;
			$(".changer-container").css("font-size",fontsize + "px");
			i = i + .2;
        setTimeout(pulseLoop, 100);    // 60fps
      }
      pulseLoop();
        
      $(document).focus();
    });