A property can be overriden by a CSS styling :
- from a CSS file
- from the "style" property
In SB 1.1, we had a Button "CSS" added on the right of the property value in this case.

In SB 2.0, the inspector design allows to add a "css" flag on the left side of the property line.
Navigation (to the css file or style property) could be done through the cog icon.