Guidance for distinctive, intentional visual design when building new UI or reshaping an existing one. Use whenever the task produces or modifies anything a user will see rendered — websites, landing pages, web apps, dashboards, React/HTML/Vue components, artifacts with visual output, style overhauls, or "make this look better" requests — even if the user never says the word "design". Covers aesthetic direction, typography, environment constraints (fonts, Tailwind, assets), and when to converge on convention instead of chasing distinctiveness.