Relative & Responsive issues

Hi all ! I manage to edit one theme to fit my needs, but now i m facing two issues.First is that the whole site (when I increased width) is not centered.It˙s using position relative and float:left; ..the issue is that on the left side is bigger gap then on the right side.If i use margin:-10 px; inside #content-outer it looks great but then on the mobile,this -20 do some bad things as the site is aligned -20 to left.

Any idea how to work this out, i am out of ideas, and i m not so good with the coding. the site is https://neymarjunior-11.com/

Another issue for an example is here https://neymarjunior-11.com/new-stats-12/

where i was working on some match stats, which i need to make responsive for mobile, but again without any luck.

third issue ,when you open the post,below it, it is shown sidebar which after 486px width starts to drop outside of site to right

you can see it here https://responsivepx.com/?neymarjunior-11.com%2F#486×480&scrollbars