If you have a Google account, you can save this code to your Google Drive.
Google will ask you to confirm Google Drive access.
Save file as:
If you have saved a file to Google Drive, you can open it here:
Mouse over the DIV element and it will change, gradually, both in color and size!
Click the "Try it" button and mouse over the DIV element again. The changes will still happen, but only the width and height will change gradually.
The transitionProperty property is supported in Internet Explorer 10, Firefox, Opera, and Chrome.
Safari supports an alternative, the WebkitTransitionProperty property.