Mockup Builder

Create HTML mockups for your project's UI that are constrained to Theme.uss variables and designed for direct translation to Unity UI Toolkit.

Skill type: Rigid — follow exactly.

Before Starting

1. Read references/theme-variables.md for the Theme.uss variable catalog. Freshness check: verify the Last synced date is current. If the project's Theme.uss has been modified since that date, regenerate theme-variables.md from Theme.uss's :root block only (see the Freshness Check instructions in theme-variables.md).
2. Read skills/shared/uss-approximation-patterns.md to understand what CSS effects are achievable in USS and how to approximate those that aren't.
3. Read skills/mock-to-unity/references/css-to-uss-mapping.md, specifically the "CSS Properties Not Available in USS" section, for the hard-block list of features that MUST NOT be used in mockups.
4. Read existing mockups in docs/mockups/ for visual language reference — but note that mockups created before this skill may use hardcoded hex values and lack CSS variables. Use them only to understand the project's visual language (colors, proportions, layout patterns), NOT as CSS architecture exemplars.

Constraints

These are non-negotiable. Every mockup must satisfy all of them.