Please don't use id selectors in your CSS. It's confusing people.

OHAI, would you consider changing the selectors in your plugin’s style sheet to something less heavy? ID selectors will prevent being overridden by what a lot of people are supposedly trying to override them with. You can’t expect people to know that ID selectors outtrump most other selectors.
Why not give your container a class .pinterest-pinboard-container and use that?

Then replace

#pinterest-pinboard-widget-container .row { width: 195px; height: 65px; }

and the likes with

.pinterest-pinboard-widget-container .row { width: 195px; height: 65px; }

and you can expect less posts in the plugin’s support section.

Thanks!

https://www.ads-software.com/plugins/pinterest-pinboard-widget/