I would recommend setting settings for your columns separately, not via custom code you provided.
For example, select “Stretch row and content (no paddings)” for row and write margin-right via Design Options.
https://prnt.sc/jtln07 – you need to use custom css code:
.home .main-nav {
margin-bottom: 0px;
}
.home .page-content {
padding-top: 0px;
}
https://prnt.sc/jtln1t – set margin value according to this screenshot http://prntscr.com/jtlwk1
Please try – http://prntscr.com/jtlxhm
Do not forget about Custom Row Layout – https://prnt.sc/jtly7o
Regards