HTML Prototype

HTML Prototype

Build a credible model of a product decision. Match the artifact to the user's context instead of applying a recurring house style. The goal is not to make every possible screen. The goal is to make the important visual or behavioral question testable.

Choose the fidelity mode

Use one of two modes:

• Mockup: Create a polished, responsive, mostly static artifact when the open question is visual hierarchy, layout, typography, color, or product fit.
• Prototype: Create a working flow when the open question is navigation, input, state change, feedback, recovery, or transition.

Do not create a separate html-mockup skill. Do not add behavior merely to make a mockup seem more complete. If a user asks for both modes, preserve the same content and structure so changes in fidelity remain easy to compare.

Derive the direction from context

Inspect the conversation, supplied references, and project before designing. Look for design-system documentation, tokens, existing components, product screenshots, and nearby artifacts.

Authority runs in this order:

1. The user's explicit visual and functional instructions.
2. The project's established design language and interaction conventions.
3. The product, audience, content, and scenario.
4. Your own design judgment.

Before coding, settle:

• the user and critical job;
• the bounded scenario under review;
• mockup or prototype mode;
• the source of the visual direction;
• the relevant state model;
• the point where the real product would take over.

When no design system exists, create a specific direction from the subject and use case. Do not default to a gradient, a dark dashboard, interchangeable cards, or decorative metrics. A prototype for a field tool, an editorial workflow, and a financial approval should not feel like the same product.

When design-artifact is available and the visual direction remains open, read and compose it with this skill. Use it to choose the register, palette, type, and composition; keep this skill authoritative for fidelity, state, and interaction completeness.

Scope one credible experience

Choose the smallest flow that can answer the review question. Use realistic, internally consistent names, dates, statuses, quantities, and copy.

• Make navigation work for the modeled scope.
• Implement forms with labels, validation, submission feedback, and sensible defaults.
• Use dialogs only when interruption or confirmation is part of the scenario.
• Use transitions to clarify continuity or state change, not as decoration.
• Remove dead buttons. If an action belongs to the real system, explain the boundary instead of pretending it completed.

Model relevant states

List the states before building. Include the states that the chosen scenario can actually reach:

• loading;
• empty;
• error;
• success;
• disabled;
• mobile;
• domain-specific states from the brief.

An asynchronous-looking prototype action should normally show loading, success, and failure or recovery. A collection should normally consider empty state. A gated action should show why it is disabled. Do not force irrelevant states into the main flow just to satisfy a checklist. Make omitted states explicit in the handoff.