This course experience report details an approach for teaching Cascading Style Sheets (CSS) constrained by the rules of objective typography. The approach condenses CSS to a human-scaled but representative subset of fewer than a dozen properties, which students then apply to a fundamental problem of visual communication: setting text that is accessible and readable across the range of screens on web-enabled devices. Students discover how to determine rule-governed values and ratios according to typographic principles, which are in turn applied and modified in a predictable, mathematically harmonious way across an entire website via its style sheet. Students learn how to verify visual results under particular viewing conditions before refactoring their work to accessibly engineer the web for diverse groups of human users. Experiential evidence suggests that these techniques transfer to other aspects of CSS, but formal study is needed.