Curious about the design behind loc.gov? SiteFontCheck scanned their live CSS architecture and identified 3 unique font families. The website relies heavily on <open sans, arial, helvetica, sans-serif> for its main text elements, paired with <roboto slab, arial, helvetica, sans-serif> and <helvetica, arial, serif> as fallback options. Below is the precise map of font sizes, weights, and text elements used across their site.