Are font sizes only global in Notepad ++?
It seems that the only way to change font size is by doing the global setting. I cannot change the size of individual words.
This is possible for certain list of words, e.g. all strings, all comments, etc.
Open Settings → Style Configurator, and for Global Styles, make sure Enable Global Font Size is not checked
In the Language and Style lists on the left, select the language and style of word for which you want to change the font size. Select a font size on the right.
Here's an example for an HTML file with a larger font for attribute 'words':
