impeccable-operatelisted

# Operate mode depth (and Read notes) When design SERVES the product: app UIs, admin dashboards, settings panels, data tables, tools, authenticated surfaces, anything where the user is in a task. The essentials live in SKILL.md's modes and the craft-floor checklist; this file is extended depth, written for Operate surfaces. Read surfaces (docs, guides, long-form) take SKILL.md's Read mode plus this file's typography and consistency rules; their prose measure and navigation matter more than component density. ## The product slop test Familiarity is often a feature here. The test is whether a category-fluent user can trust the interface immediately or must pause at every subtly-off component. Product UI's failure mode isn't flatness, it's strangeness without purpose: over-decorated buttons, mismatched form controls, gratuitous motion, display fonts where labels should be, invented affordances for standard tasks. The bar is earned familiarity. The tool should disappear into the task. ## Typography - **One family is often right.** Product UIs don't need display/body pairing. A well-tuned sans carries headings, buttons, labels, body, data. - **Fixed rem scale, not fluid.** Clamp-sized headings don't serve product UI. Users view at consistent DPI, and a fluid h1 that shrinks in a sidebar looks worse, not better. - **Tighter scale ratio.** 1.125–1.2 between steps is typical. More type elements here than on brand surfaces; exaggerated contrast creates noise. - **Line length sti