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Bulletproof Frontend

Community
aaddrick
bulletproof-frontend

Bulletproof CSS and frontend design principles from "Handcrafted CSS" by Dan Cederholm. Apply when writing CSS, HTML, Blade templates, or reviewing frontend code. CSS is king — refactor Tailwind when encountered.

Overview

Publisheraaddrick
Repositoryclaude-pipeline
Skill namebulletproof-frontend
Stars
130
Forks
17
Bundled files
5
LicenseMIT
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • 5 bundled files

    Scripts, templates, and references the model can read while it works. Files are read-only and never executed.

  • Open source

    Published by aaddrick on GitHub. Read the source before you install it.

Installation

Install the Bulletproof Frontend AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/aaddrick/claude-pipeline/tree/main/.claude/skills/bulletproof-frontend
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/aaddrick/claude-pipeline.git /tmp/claude-pipeline
mkdir -p .claude/skills
cp -r /tmp/claude-pipeline/.claude/skills/bulletproof-frontend .claude/skills/bulletproof-frontend
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Bulletproof Frontend in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Bulletproof Frontend on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Bulletproof Frontend is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Bulletproof Frontend Design

CSS is king. Semantic, maintainable CSS over utility-class frameworks. When you encounter Tailwind, refactor it to proper CSS.

Design Values: For spacing scales, typography sizes, color palettes, contrast ratios, and component specifications, see ui-design-fundamentals. This skill focuses on CSS implementation patterns.

Core Philosophy

"Always ask: What happens if...?" — Design for the unexpected. Build interfaces that remain functional and readable regardless of content length, text size, browser, or device.

The Three Pillars

1. Bulletproof Design

  • Design for flexibility, not fixed scenarios
  • Test with varying text sizes and content lengths
  • Use relative units (em, %, rem) over fixed pixels

2. Progressive Enrichment

  • Reward capable browsers with advanced CSS
  • Websites don't need to look identical in every browser — they need to be functional
  • Use modern CSS with appropriate fallbacks

3. Reevaluate Past Methods

  • Question whether old hacks are still necessary
  • Simplify where new CSS features allow
  • Refactor utility frameworks to semantic CSS

Quick Reference

PatternWhen to Use
CSS custom propertiesTheming, spacing, colors
BEM namingComponent class structure
Cascade layersManaging specificity
Container queriesComponent-based responsiveness
:has() selectorParent/sibling selection
CSS nestingOrganizing related styles

Modern CSS Essentials

css
/* :has() — Style based on children */
.card:has(img) { padding-top: 0; }
.form:has(:invalid) { border-color: var(--color-error); }

/* Container queries — Component responsiveness */
.container { container-type: inline-size; }
@container (min-width: 400px) { .card { display: flex; } }

/* CSS nesting — Clean organization */
.card {
    padding: var(--space-md);
    &:hover { box-shadow: var(--shadow-lg); }
    & .card__title { font-weight: var(--font-bold); }
}

/* Cascade layers — Controlled specificity */
@layer reset, base, components, utilities;

Tailwind → Semantic CSS

blade
{{-- BEFORE: Utility classes --}}
<div class="flex items-center p-4 bg-white rounded-lg shadow">

{{-- AFTER: Semantic CSS --}}
<div class="card">
css
.card {
    display: flex;
    align-items: center;
    padding: var(--space-md);
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}
CSS ApproachTailwind
Readable HTMLBloated class attributes
Styles in one placeScattered in markup
Easy to refactorFind-and-replace nightmare
Cacheable stylesheetsRepeated classes

Reference Files

FileContent
css-architecture.mdCustom properties, BEM, layers, file organization
accessibility-patterns.mdFocus, screen readers, motion, dark mode
responsive-patterns.mdBreakpoints, container queries, fluid sizing
reference.mdComplete patterns and Blade components

Project Style Guide

Project-specific implementation: docs/STYLEGUIDE.md

Contains the complete design system for the application:

  • Design tokens (colors, spacing, typography)
  • Component patterns (buttons, cards, alerts, tables)
  • Blade component documentation
  • Dark mode implementation
  • Accessibility requirements

Always consult the style guide when implementing UI to ensure consistency with existing patterns.

Related Skills

  • ui-design-fundamentals — Design values: spacing scales, type scales, colors, contrast ratios, component anatomy (buttons, forms, cards, etc.)

Bundled files

The model reads these on demand while the skill is loaded. They are exposed as readable files and are never executed.

Frequently asked questions

What does the Bulletproof Frontend AI skill do?

Bulletproof CSS and frontend design principles from "Handcrafted CSS" by Dan Cederholm. Apply when writing CSS, HTML, Blade templates, or reviewing frontend code. CSS is king — refactor Tailwind when encountered.

Why use Bulletproof Frontend on TypingMind?

Because you install it once and use it with any model. Bulletproof Frontend is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Bulletproof Frontend in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/aaddrick/claude-pipeline/tree/main/.claude/skills/bulletproof-frontend. TypingMind reads its SKILL.md and bundles its files and installs it as a skill you can enable per chat.

Which AI models can use Bulletproof Frontend?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Bulletproof Frontend?

As many as you like. As long as a model supports skills, you can use Bulletproof Frontend with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Bulletproof Frontend AI skill free?

Yes. It is published on GitHub by aaddrick under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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