The HTML file contains a rudimentary HTML5 document structure, with all the every day stuff like title, header, footer, etc. It also uses conditional comments to call about half a dozen IE-specific CSS files, as well as a couple popular IE-correcting javascript files.
All supporting files are stored in a parent “_” folder — this keeps the view in our file manager uncluttered. We could call it something like “assets,” but we prefer to give it a name that ensures it stays at the top of the list (which is why the CSS folders are prefixed with underscores).
In the CSS folders are baseline styles designed to reduce the visual design in any browser to its most basic state. This frees you from the annoyance of overcoming the native styling that each browser wants to apply to HTML elements such as h1, p, and ul. From this starting point it’s very easy to establish your own standards for type size, margins, and other measurements.