I have not been able to find a website that lists percent of each malt and/or adjunct for a given style of beer. Is there such a site?
I'm not sure you're going to find anything besides recipes that are especially prescriptive about what goes in to the beer. Check out BeerSmith, BrewToad, and other sites to find some recipes. They will give you some concrete examples of grain bills for a style.
If you're looking for something more broad, check out the BJCP style guidelines, especially the style guide with ingrediant comments. These are much more general and illustrate that most styles have a wide range of acceptable ingrediants.