If you are actually asking if you can make a phrase with 10 words be as long as phrase with 5 words (apart from making the font half the size for these), this is not with CSS, but with Harry Potter 🙂 Joke aside, even it the font size could adapt based on the length of the title, I don’t think it would look nice.
A better (and feasible solution) would be to have purple title bars to all have the same height regardless of how much text is in them. That we can do with the rule below in Main options > Post Specifics > Post Title > Post Title BG CSS+ box
{min-height:55px;}
To make sure they are always aligned between columns, you would need to use display post as two columns but not masonry.