Hopefully someone can help me.

https://www.latexmattresswarehouse.com.au when viewed in the preview section of WP sits correctly on mobile devices. However when I view it on my iPhone (or any mobile) device the page has a margin to the right hand side and the nav bar only fits half of the left side.

Can anyone point me in the right direction to make the mobile page fill the whole page and the nav bar fill the whole page also when selected?

Many thanks, I have been in all the menu settings but seem to think its something a little more tricky

Using child theme inherited from shopstars theme.

Thanks to anyone who reaches out to help me in advance.

It’s probably set in header.php somewhere.