Robots & Sitemaps & SEO?
You can create classes of styles that can then be used on many different HTML elements with a single change to the style sheet. a consistent appearance and feel across multiple web pages faster load times because the CSS file is only downloaded once and applied to each relevant page as needed.
A Sitemap is a list of web pages within a domain. There are three types of sitemaps: Sitemaps are used by web designers to plan the layout of a website. Human-readable listings of a site's pages, typically hierarchical. Structured listings for web crawlers like search engines.