Full page design and responsive

Hello, I are working on a web site design and I want to have a login/registration page like the Hubstaff example https://account.hubstaff.com/login 1 I came up with this design (see attached) but it is not responsive like Hubstaff and I am trying to come up with a solution. Does anybody know how can I fix this in order that the form on the left remains of a same size? Thanks

I know there is bootstrap up to 1140. But I want to have the design cover the entire page. Not just in a container.