How can we expand the lightning component to full screen

Question

I have the requirement to expand the lightning component on whole screen. I tried the css but that's not worked. But None of them working .maincontent{ height: 100%; background-color: deepskyblue; }

html, body { height: 100%; }
body { background-color: deepskyblue; }



Please suggest the way to achieve it.

Current Page:-

[![Current][1]][1]


Expectation :-
[![Expectation][2]][2]


  [1]: https://i.stack.imgur.com/iuI6K.png
  [2]: https://i.stack.imgur.com/qLZhs.png