Site Design for improved SEO

Has anyone found any seemingly concrete data or a study or even personal experience that shows that certain front-end designs will help with SEO? From just an off the cuff perspective, it seems like Google would value a nice looking website, but that variable could be considered the most subjective of them all. I've seen 100s of variables people suggest as ranking factors, but never really seen site design being talked about much. I have had what I thought were crappy looking sites rank well, but then eventually dropped, but too many variables to say that's why.

Does anyone have an idea?

I don't think it matters that much.

I mean, I saw websites ranking in top 3 SERP and have a 1990s looking design. With stating pages and small fonts.

Although I would love google to give some ranking power to design, but I highly doubt it.

One of the biggest challenges that online businesses face today is maintaining relevance in the eyes of the search engines, especially Google.It’s a well-established principle that on-site SEO is one of the most basic building blocks every business needs to have as they start on the road to search engine domination. So it makes sense to add another string to your own marketing bow as a web designer and incorporate some simple SEO strategies into every web design you deliver.

i don't think the design influence the SEO ..... its the code structure.

if you are in WP then there is not much to do but if you are in html i prefer where the main blog is in front and the sidebar is low in the script.

The design will not grab more attention but it has some percent attention and in indirect factor, you can consider the page loading speed.Bounce rate may have chances of getting an increase if loading speed is more.Make your site short and sweet.