Site isn’t live yet, so no link to share. I don’t see how that’s relevant to my question, regardless.
Why a background image? I’m simply asking for an option to provide a default thumbnail that will display with the Popular Posts widget if the entry does not include a featured image.
A default thumbnail is a standard feature of the original Popular Posts plugin, as well as most of the “related posts” plugins available via WordPress.
I have notified this to the theme developer by creating feature request for it on the following page.
The feature request will be developed in the future version of theme.
Very good!
In the meantime, I’m using the WordPress Popular Posts plugin and have applied some of the border-radius, margin and transition CSS you’re using with Sparkling Popular Posts.