CSS text width left to right

I'm trying to fade in text from left to right similar to answer found here, but want the text to be hidden behind a transparent background div instead of the example's white background. Is this possible with CSS? Reason being there will be a image behind the text that I'd like to fade in.

Solution

Yes, you can simple make it by setup the width from 0 to 100% on @keyframes (as in example in your question) to show the parts of the text.

Small demo-example for you to show is how it work. Click on Zero:

stripe.onclick = function() {
  var sec = new Date().getSeconds() % 10;
  stripe.classList.add('animate');
  digit.classList.add('animate');
  console.log();
};

	#digit {
	  width: 20px;
	  overflow: hidden;
	  font: 32px "Courier New", monospace;
	  cursor: pointer;
	  transition: 2s linear width;
	}

	#stripe {
	  width: 20px;
	  transition: 2s linear width;		
	}

	#stripe.animate {
	  width: 200px;
	  transition: 2s linear width;
	}

	#digit.animate {
	  width: 200px;
	  transition: 2s linear width;
	}

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Title</title>
  <style>
  </style>
</head>
<body>
	
  <div id="digit"><span id="stripe">0123456789</span></div>

<script>
</script>
</body>
</html>

P.S.

JS only for test. By @keyframes you do not need them.