Bootstrap.css not functioning fully

[abhijeet]

Hi,

I used below example - same code and everything but when run in apache 2.4 

Example which I exactly copy pasted. 

https://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_navbar_collapse&stacked=h

it shows - 

it is not taking all bootstrap.min.css contents; Any advice or suggestions are welcome.