Ryan Boudreaux includes all the code snippets you'll need in this demo of how to create an image hover-preview effect using HTML, CSS, and JavaScript.

Open your website's stylesheet in Notepad or your code editor. At the top of the code, write a style rule setting the entire page and HTML body to 100 percent height:html, body { height: 100%; } ...

Set your image up within your text and add a "style" attribute tag. For instance, the HTML code for your image might look something like this: Define the border within the "style" attribute.