An overlay allows an asset to be emphasized by rendering it on top of the rest of the site's content while also obscuring the area around the asset. Video playback, image expansion, PDF, and HTML packages are rendered in an overlay with Zoomforth.
Design customization for overlay assets can be done using CSS classes.
To add a CSS class for an overlay asset on image expansion:
Click the image you want to open in overlay or expansion.
Click the Action tab.
Under On click, select Expand Image, then click Edit/Preview.
In the CSS Classes field, enter the class to use for the overlay asset.
Click Finish Editing, then click Done Editing Tile.