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:
Gradually change the font-weight from normal to bold, and back to normal:
This is a paragraph
The font-weight is animatable in CSS.
Note: CSS Animations do not work in Internet Explorer 9 and earlier versions.