Help me design a button/CTA system.
CONTEXT: [[PRODUCT]]
BRAND COLORS: [[COLORS]]
BUTTON USES: [[USES]] (primary actions, destructive, secondary, links…)
Deliver:
1. A button hierarchy (primary/secondary/tertiary/destructive) and when to use each
2. Sizing, padding, radius, and state styles (hover/focus/active/disabled/loading)
3. CTA label rules (verb-first, specific, length)
4. Placement and "one primary action per view" guidance
5. Accessibility (contrast, focus, touch target size)
6. Common mistakes (too many primaries, vague labels)