Emphasise the active investigation card through stronger elevation,
clearer borders, and improved spacing. Quiet supporting panels by
reducing border opacity, softening heading weight, and lowering
text contrast — making them available without competing for attention.
Facilitator card receives a warm surface tint to read as a briefing
card rather than a generic panel.
Documentation: close experiment 05 with findings, add experiment 06
to the design evolution log, add Attention Hierarchy to UX guidelines,
defer dark mode to a future Investigation Mode experiment.
Presentation changes only — no reasoning, prompts, graph, API, or
backend modifications.