Sunnyside agency landing page with HTML & CSS

So, my main question would be : how to use container by the same way bootstrap do ? I mean, I definided some width to my page to be as close as the design at possible, but I guess it would be better if my colors continue on right and left, instead of this black background. How can I define a nice wrapper in native HTML/CSS ?

Also, I wanted to animate my toggle burger-menu, but I struggled because of display: block... any suggestions ?

However, pretty interesting and real-sized exercice ! Liked it, altrough it was a bit long !