Problem:
I am trying to get as close to 100% consistency of font sizes and weights when translating English to Chinese. Instead I got lots of inconsistencies occur especially in the title.
Solution:
This seems to be related to the font and the weight that you're using. Things are looking better when decreasing the font weight. In this case, change change the font to a most common one (like Open Sans), and the text should look better this time.
