# 17 · Digital · UI

**PRINCIPLE** — Components are containers for facts.

**RULE** — Build only from tokens and .msz-* components. Radius 0 (2 px inputs/chips). One primary button, one red signal per view. Error = red border + black text.

**WHEN TO USE** — Website, booking, member portal.

**WHEN NOT TO USE** — Social artwork.

**DO**
- Visible focus on everything
- Status text with every colour

**DON’T**
- Pills, card shadows
- Red links or red error text

**EXAMPLE** — See board Web (15), components (16, 22).