Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add oborchers/fractional-cto --skill responsive-designgit clone --depth 1 https://github.com/oborchers/fractional-ctoWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/oborchers/fractional-cto/responsive-design)<a href="https://agentmods.dev/skills/oborchers/fractional-cto/responsive-design"><img src="https://agentmods.dev/badge/skills/oborchers/fractional-cto/responsive-design/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/oborchers/fractional-cto/responsive-design"><img src="https://agentmods.dev/badge/skills/oborchers/fractional-cto/responsive-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00087 | $0.02109 |
| Opus 5.5 | $0.00035 | $0.00844 |
| Sonnet 5.5 | $0.00017 | $0.00422 |
| Haiku 4.5 | $0.00009 | $0.00211 |
Grade A, and why
responsive-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 176 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Mobile-First Is Not a Technical Strategy — It Is a Content Strategy
Mobile-first forces content prioritization. When you design for 320px first, you must decide what actually matters. Desktop is the easy case — there is room for everything. Mobile reveals what is essential. Start narrow, enhance wide. Use min-width media queries exclusively (progressive enhancement).
Breakpoint Reference
Define breakpoints based on common device classes. Use min-width (mobile-first) exclusively.
| Name | Range | Min-Width Query | Typical Devices |
|---|---|---|---|
| xs | 0-479px | (base styles) | Small phones |
| sm | 480-639px | @media (min-width: 480px) |
Large phones |
| md | 640-767px | @media (min-width: 640px) |
Small tablets |
| lg | 768-1023px | @media (min-width: 768px) |
Tablets, small laptops |
| xl | 1024-1279px | @media (min-width: 1024px) |
Laptops, desktops |
| 2xl | 1280px+ | @media (min-width: 1280px) |
Large desktops |
Rule: Design for xs first. Add complexity at each breakpoint. Never start with desktop and subtract.
Fluid Grids
Use CSS Grid auto-fit/auto-fill with minmax() for grids that reflow without media queries. Use clamp() for fluid sizing that interpolates between a minimum and maximum.
/* Responsive card grid — no media queries needed */
.card-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
gap: 24px;
}
/* Fluid container padding */
.container {
padding-inline: clamp(16px, 4vw, 48px);
max-width: 1200px;
margin-inline: auto;
}
Container Queries
Container queries decouple component responsiveness from the viewport. A card in a sidebar and a card in the main content area can respond to their own available space.
.card-wrapper {
container-type: inline-size;
container-name: card;
}
@container card (min-width: 400px) {
.card { flex-direction: row; }
}
@container card (max-width: 399px) {
.card { flex-direction: column; }
}
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 176 lines · 87 tokens per session scan A f87e1c6d804a
responsive-design is a skill published in the GitHub repository oborchers/fractional-cto (32 stars, last pushed 5d ago), licensed MIT. It adds 87 tokens to every session and 2,109 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-13.
Other skills, from other repositories
anti-slop-design
Autonomous Principal Design Technologist. Cures vibe-coded software from AI frontend slop using curated token archetypes and 7-axis quality gating.
chakra-ui-builder
Build responsive, accessible UI components and layouts using Chakra UI v3, install or configure Chakra UI in new and existing projects, and design scalable themes using tokens, semantic tokens, recipes, and slot recipes. Use this skill whenever a user asks to build, create, or generate any UI component, page, form…
visual-ralph
Visual Ralph orchestration for frontend UI from generated references, static references, or live URL targets, using $ultragoal with built-in visual verdict and pixel-diff evidence until the implementation matches and leaves a reproducible design system.
frontend-ui-dark-ts
Build dark-themed React applications using Tailwind CSS with custom theming, glassmorphism effects, and Framer Motion animations. Use when creating dashboards, admin panels, or data-rich interfaces with a refined dark aesthetic.
prototype-web
A clickable, high-fidelity web product prototype with navigation, a hero section, feature cards, steps, social proof, and optional pricing. It is designed to resemble a finished landing page while remaining a prototype.
frontend-visual-qa
Audits rendered UI and specific task/object-link handoffs; excludes ordinary source citations alone. Audits already-rendered UI and Markdown/Obsidian image layout — web app, deck/slide, dashboard, design-system, or Electron/native app — via real-browser/native-app journeys and a Playwright sweep. Use after UI…