What,according to you, is the underlying theme of Twilight?

If you're forced to সরানো in with your father, আপনি may just end up with a family of vampires, who are hated দ্বারা your bff werewolves, but it'll work out because one of them will fall in প্রণয় with your daughter. ._.

Life choices/free agency.
আপনি don't have to accept অথবা take what's handed to you. আপনি always have the option to make what আপনি want happen.
The Cullens chose to deny their nature and have high morals.
The choice to resist temptation.
Bella chooses Edward, despite the odds being stacked against her.
And so on.

The opposite is demonstrated with the Quilieutes (I always spell that word wrong). I think it adds to the theme, প্রদর্শিত হচ্ছে what life would be like if আপনি didn't have many choices.

That's the main one, I think.