Jono: Google tries to understand pages like humans do. They have a famous patent called The Reasonable Surfer. Here, they look at the layout of the page and try to assess what’s what. They know that a link in a photo is probably less relevant than a link in the header. They go further than that. We know they render the page, we know they process and parse all the CSS, we know that broken layouts and hiding things impact things. So yeah, they are looking at the design. How that manifests in the system: who knows. Your CSS might impact your rankings. So if you have an ugly shade of pink as the background for your page or all your stuff is moving or half of it is invisible, that's an issue.