/* Paper treatment over vis-timeline (Task 7). Borrows the archive's palette (assets/site.css :root), rule weights and mono type rather than inventing new ones. vis ships 88 selectors, all namespaced .vis-*, so this is additive: nothing here removes a vis class, it only repaints what's already there. Every rule below is scoped under .timeline-stage (the section wrapping both #timeline-events and #timeline-density). This isn't just tidy namespacing: the vendored vis-timeline-graph2d.min.js re-injects its own copy of vis's default CSS as