If you have very long words (or more likely links) inside the new Vector styling, these can now overflow the intended width. This looks weird and should likely be countered with overflow-wrap: break-word on mw-content-container
Without break word
With break word
Example
https://books.google.com/books?id=sDeE9r_6HdsC&pg=PT234&lpg=PT234&dq=Jiyu+hiwar&source=bl&ots=uqCPAz1gx6&sig=2ZDD2RkxILyXnIqm0o42i5PfndU&hl=en&sa=X&ved=0CBwQ6AEwAGoVChMI3qqt6NvhyAIVxWQsCh07igs-#v=onepage&q=Jiyu%20hiwar&f=false