Browsers default CSS for HTML elements

Question

Where can I discover the default CSS for HTML components in a browser?

Many HTML elements include some default CSS properties, which can occasionally lead to unexpected or undesirable behavior. For instance, various browsers show input boxes differently. I'm trying to find a place that discusses the new HTML5 components and CSS3 attributes.

I've seen responses to queries that propose a CSS reset in other (far older) topics, such as Browsers' Default CSS Stylesheets. Sometimes I don't want this solution; instead, I would prefer to maintain some of the fundamental characteristics (such as the highlighting of input boxes in Chrome). In other words: Just because I don't know what something does, I don't want to get rid of it.

So, Is there a site that can give me all this information (or perhaps most)?