How to make logo position to center mobile view?

Here is my site: https://www.lantangriau.com

not sure what you mean? its center enough for me in mobile.

I mean the logo not display in center position in mobile view, as you could see in the screenshot above.

Oh ya, so what’s might wrong in my site?

add this to wp-admin->appeareance->theme option->custom css

@media only screen and (min-width:240px) and (max-width:550px){
#siteinfo { margin:0 !important; }
}

Thank you Richie.
Please also help answer my question about image caption.