web-design-guidelines

A set of rules for designing and reviewing websites that work across screen sizes, load efficiently, and remain usable for people with disabilities.

In plain words
What is it for?
Use it when building or auditing HTML, CSS, web components, responsive layouts, accessibility, or web performance.
Why use it?
It helps prevent inaccessible interfaces, poor mobile layouts, slow pages, and web code that ignores established accessibility guidance such as WCAG.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/chama-x/groundrules/web
Any agent
npx skills add chama-x/GroundRules --skill web
Clone the repo
git clone --depth 1 https://github.com/chama-x/GroundRules

Made for: Claude Code, Codex.

Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 10,504 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00054 $0.10504
Opus 5 $0.00027 $0.05252
Sonnet 5 $0.00011 $0.02101
Haiku 4.5 $0.00005 $0.01050

Measured 2d ago against content hash bbdf17699240, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

web-design-guidelines scanned grade A with 1 finding 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 2d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

caches.match(e.request).then(hit => hit ?? fetch(e.request))
Origin

This is a copy

100% identical to web-design-guidelines — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/archive/v3/skill_platform-design-skills/skills/web/SKILL.md · 1,455 lines

How it starts

The opening of the file, as written. The whole thing — 1,455 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Platform Design Guidelines

Framework-agnostic rules for accessible, performant, responsive web interfaces. Based on WCAG 2.2, MDN Web Docs, and modern web platform APIs.


1. Accessibility / WCAG [CRITICAL]

Accessibility is not optional. Most rules in this section map to WCAG 2.2 success criteria at Level A or AA. A small number of best-practice rules (noted inline) target Level AAA or go beyond WCAG.

1.1 Use Semantic HTML Elements

Use elements for their intended purpose. Semantic structure provides free accessibility, SEO, and reader-mode support.

Element Purpose
<main> Primary page content (one per page)
<nav> Navigation blocks
<header> Introductory content or navigational aids
<footer> Footer for nearest sectioning content
<article> Self-contained, independently distributable content
<section> Thematic grouping with a heading
<aside> Tangentially related content (sidebars, callouts)
<figure> / <figcaption> Illustrations, diagrams, code listings
<details> / <summary> Expandable/collapsible disclosure widget
<dialog> Modal or non-modal dialog boxes
<time> Machine-readable dates/times
<mark> Highlighted/referenced text
<address> Contact information for nearest article/body
<!-- Good -->
<main>
  <article>
    <h1>Article Title</h1>
    <p>Content...</p>
  </article>
  <aside>Related links</aside>
</main>

<!-- Bad: div soup -->
<div class="main">
  <div class="article">
    <div class="title">Article Title</div>
    <div class="content">Content...</div>
  </div>
</div>

Anti-pattern: Using <div> or <span> for interactive elements. Never write <div onclick> when <button> exists.

1.2 ARIA Labels on Interactive Elements

Every interactive element must have an accessible name. Prefer visible text; use aria-label or aria-labelledby only when visible text is insufficient (SC 4.1.2).

Read the full file on GitHub · 1,455 lines

Files

What ships with it

3 files 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.

Changes

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.

  1. 2d ago First seen · 1,455 lines · 54 tokens per session scan A bbdf17699240

Subscribe to this mod's changes

web-design-guidelines is a skill published in the GitHub repository chama-x/GroundRules (5 stars, last pushed 18d ago), licensed MIT. It adds 54 tokens to every session and 10,504 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to web-design-guidelines, differing in 0 lines, and is treated as a copy.