Hi,
unfortunately, we can’t access to your WordPress right now, check your credentials.
We see that you use boxed body.
Please open your style.css file
and on line 6280 you have Responsive css. Remove all code from that line till the end of style.css file.
In attachment we are sending you just_responsive_css.css. Open that file, copy all code from there and then paste it instead code from style.css that you removed.
Now should all works fine if you have not worked any customization for responsive.
Let us know if you need anything else :)
Kind regards