Use these 3 files to make AI-built apps look less generic

Short answer

Your AI-built app looks generic because the AI is designing from vague instructions.

When you ask for "clean, modern, premium, simple" UI, the model usually falls back to the same safe ingredients: rounded cards, generic gradients, default fonts, predictable dashboards, and layouts that feel copied from every other AI demo.

The fix is to stop treating design as one prompt. Give the AI a reusable design context: a DESIGN.md file, an HTML reference, component rules, and a review loop.

The better workflow

The better workflow is simple: stop asking AI to invent taste from scratch.

First, create a DESIGN.md file that captures the brand’s visual personality. Second, give the agent an HTML reference that shows what finished output using that system should look like. Third, add a skill or prompt rule that tells the agent how to apply the design system every time.

In plain English: give the AI taste as context, then reuse that context across screens, apps, decks, and landing pages.

Why vague prompts fail

NN/g makes the same point from a UX angle: vague AI prototyping prompts fail because words like "modern" or "minimal" are too broad. Better prompts point to recognizable design styles, frameworks, or visual references.

That matters for vibe coding because design quality is not only color. It is typography, spacing, hierarchy, density, states, empty states, motion, interaction patterns, and what the interface should feel like for the user.

If you do not provide those choices, the model will fill the silence with defaults.

Sources: NN/g: Prompt-to-design interfaces

What a DESIGN.md file does

A DESIGN.md file is a small design system written for an AI coding agent. It tells the agent what the interface should feel like before it starts writing components.

This is just context engineering applied to design. Instead of repeating taste preferences in every chat, you save them in a reusable file and attach or reference it whenever the agent builds UI.

Why references matter

The transcript’s second layer is the HTML reference. This is important because instructions describe taste, but references show taste.

A finished HTML reference can show the agent how spacing, components, typography, and density work together. It becomes a target, not just a mood.

Material Design describes a design system as reusable design decisions expressed as guidance, components, and patterns. That is the same principle here: give the agent reusable decisions so it does not improvise every screen.

Sources: Android Developers: design system overview

The three-file workflow

If you want a simple process, use three files or blocks of context before asking the AI to build the next screen.

This turns a one-off prompt into a reusable frontend workflow.

A starter DESIGN.md

You can start with a short version like this.

• Product: what the app does and who uses it.
• Design direction: three adjectives plus what those words mean in UI.
• Layout rules: density, spacing, navigation, and responsive behavior.
• Component rules: buttons, cards, tables, forms, tabs, modals, charts, and empty states.
• Typography rules: heading scale, body size, button size, and line height.
• Color rules: brand colors, neutrals, accent use, contrast, and palettes to avoid.
• Interaction rules: hover, focus, loading, success, error, and disabled states.
• Do-not list: patterns that make the app feel generic.
• Review checklist: what the agent must check before calling the UI done.

Prompt example

Here is the practical prompt pattern.

Use it when you want Claude Code, Codex, Cursor, Lovable, Bolt, or any AI builder to produce less generic UI.

• Read DESIGN.md first.
• Study the HTML reference and identify the design patterns it uses.
• Build the requested screen using the existing app structure.
• Keep the UI appropriate for the product category and user workflow.
• Avoid generic AI-app patterns listed in DESIGN.md.
• After building, compare the output against the reference and list what you improved.

Sources: Claude Code best practices

What to avoid

Most AI-built apps look generic because the design direction is too thin.

Do not fix that by adding more adjectives. Fix it by adding constraints, references, and review criteria.

• Do not say only "make it modern."
• Do not ask for a landing page when you need a real app screen.
• Do not let every tool become a card grid.
• Do not use one color family everywhere.
• Do not accept the first version without a screenshot review.
• Do not mix unrelated inspirations in one prompt.
• Do not ask the AI to be creative without saying what kind of creativity fits the product.

The screenshot review loop

The final step is visual review. AI cannot reliably judge its own UI from code alone. Open the screen, take a screenshot, and ask what looks generic, misaligned, oversized, crowded, or off-brand.

Then make one focused design pass at a time: layout, typography, color, component states, mobile fit, and final polish.

This is where vibe coding becomes a real build process. You are not just prompting. You are giving direction, checking output, and tightening the result.

Final answer

Your AI-built app looks generic because the AI is guessing your design taste.

Give it a reusable DESIGN.md, a finished reference, component rules, and a screenshot review loop. That turns design from a vague prompt into reusable context. The more specific the taste system, the less your app looks like everyone else’s AI demo.