Corp Theme: Centre-Align Logo on Mobile?

I’ve been trying to center align the logo for mobile site (using SitOrigin Corp).

I used the following CSS but the logo was not going in the true center, instead it seemed to be the center of the space between the left side of the header and the nav icon – therefore appearing to the left slightly.

@media (max-width: 650px) {
	.site-branding {
		text-align: center;
		width: 100%;
 }
}

Result when CSS added: Screenshot