Design Fundamentals — Agent Instructions
Universal design principles that define why patterns work, how to apply them correctly, and what accessibility requirements are non-negotiable. These are timeless, design-system-agnostic foundations that apply to every surface regardless of vertical or workflow phase.
Load order
Read these files after loading the design system (SKILL.md / DESIGN.md + token modules). The design system tells you what token to use; these files explain why that decision is correct and how to avoid common principle violations.
Module index
| File | Purpose |
|---|---|
| ui-principles.md | Universal visual design principles — hierarchy, layout rhythm, typography placement, color theory, depth & layering, interaction design, responsive adaptation, component behavior |
| spacing-principles.md | Spacing-specific principles — 4-point grid, proximity grouping, inner vs outer gaps, vertical and horizontal rhythm, heading→paragraph spacing, section and component spacing tiers |
| ux-principles.md | Interaction & control principles — 30 UX laws, button/control state contracts (9 states), hover/active technique palettes, touch targets, cognitive load, feedback loops |
| typography-principles.md | Typography-specific principles — type system foundations, scale & modular ratios, readability & measure, accessibility, responsive type, brand tone expression through type |
| accessibility.md | WCAG 2.1/2.2 compliance — contrast ratios, color-as-information rules, focus visibility, keyboard navigation, motion safety, target sizes, text spacing, semantic structure, ARIA |
What these files are NOT
These files do not define:
- Workflow phases (think → build → check → ship) — see
skills/vertical/SKILL.md - Quality gates or audits — see
skills/vertical/inspect.md,review.md,preflight.md - Anti-pattern catalogs — see
skills/vertical/anti-patterns.md - Industry-specific content — see
skills/vertical/team-social-saas.md - Design tokens or component specs — see
skills/design-system/SKILL.md
Conflict resolution
When sources disagree:
- Design system wins for concrete values (colors, sizes, spacing tokens, component specs).
- Fundamentals (this layer) win for structural principles (hierarchy, accessibility, motion logic).
- Vertical wins for process decisions AND content architecture (section order, required sections, industry tone).
Accessibility is non-negotiable at every level — it overrides aesthetic preferences everywhere.
When the design system is silent, these principles decide
Any design decision not covered by the system's tokens or component rules falls back to the principles here. Never contradict the design system — if a principle and a design-system rule conflict, the design system wins. Flag the conflict for review.