Interactive charts and a perfect Lighthouse run often feel incompatible. The usual path is a 50–150 KB chart library, hydration, and a blank box until JavaScript finishes. You can still offer real visuals and light interaction without paying that tax on every page load. This article is about a paint-first pipeline: compile data to HTML/CSS, let the browser draw on first paint, then add interaction as progressive enhancement. The real performance problem Core Web Vitals ...