Different displaying web page by asp net app

I have a problem.

I started to learn bootstrap on some themes which I found in web. But if i trying to open this in browser its look good, but if i use it like a asp net view , something is making this gap.

At the beginning and thought it because of missing CSS file but i included all.

  • Bootstrap is updated
  • My custom CSS added to bundle

On the picture u can see this gap: https://i.stack.imgur.com/0A6rt.png