> most users don't customize their default fonts, resulting in sans-serif mapping to Arial (unstylish), and monospace mapping to Courier New on Firefox (painful

> most users don't customize their default fonts, resulting in sans-serif mapping to Arial (unstylish), and monospace mapping to Courier New on Firefox (painfully thin to read) I lean towards defining a font stack for this reason. It would be nice if there were a way to specify user-defined font vs. default font in CSS so something like font-family: user-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Liberation Sans", sans-serif; would use a user-defined sans serif if possible, but fallback on a font stack for users with no custom font setting.