Modern Web Guidance

# Modern Web Guidance

A skill to search for specific web development use cases and retrieve their corresponding best practice guides.

## When to use

Must use this skill:
- At the **start** of implementing any web feature.
- Before creating a new component, to check if a standardized pattern already exists.
- To avoid implementing ad-hoc solutions or loading large dependencies unnecessarily.

## Usage Instructions

### Step 1. Search Use Cases

Search with an action-oriented query summarizing what you want to achieve using the `search` command. Run `modern-web-guidance` directly with `npx`.

```sh
npx -y modern-web-guidance@latest search "<query>" --skill-version 2026_05_16-c5e7870
```

**Example Output**:
```json
[
  {
    "id": "optimize-image-priority",
    "description": "Optimize the loading priority of Largest Contentful Paint (LCP) candidate images.",
    "category": "performance",
    "featuresUsed": [ "Fetch priority" ],
    "tokenCount": 985,
    "similarity": 0.7289
  },
  {
    "id": "defer-rendering-heavy-content",
    "description": "Reduce rendering times in content-heavy web pages by deferring rendering for offscreen content.",
    "category": "performance",
    "featuresUsed": [ "content-visibility", "hidden=\"until-found\"" ],
    "tokenCount": 1250,
    "similarity": 0.6961
  }
]
```

> **Note**: If search results are vague, return no matches, or show low similarity scores, run the `list` command to browse all guides:
> ```sh
> npx -y modern-web-guidance@latest list
> ```

---

### Step 2. Retrieve Best Practices

Once you have a relevant `id` from the search results, call this script using the `retrieve` command to get the full guide. You can pass multiple IDs separated by commas.

```sh
npx -y modern-web-guidance@latest retrieve "<id>"
```


**Example Output**:
`The markdown content of the guide describing implementation steps...`

## Using npx

-   IMPORTANT: on Windows, using `npx` may fail. Use `npx.cmd ...` instead.
-   Network access is required for fetching npm packages needed by the task.
-   If the `npx -y modern-web-guidance…` command hangs, you may be offline. Try running again in offline
    mode: `npx --offline …`.
-   The `--skill-version` flag is used to determine if this SKILL.md is out of date. If it is, a warning
    message is logged to stderr.

## Guidelines

-   Always search **first** to find the most relevant guides.
-   These guides are usually framework-agnostic; adapt them correctly to your setup.
-   Do not hallucinate guides or ignore them; they represent the preferred local standard for the user's project.


## Interpreting Browser Support & Fallbacks

* **Default Behavior**: All guides assume **Baseline Widely available** features are safe to use without fallbacks. For features that are not Baseline widely available, you **MUST** follow the fallback recommendations in the guide, unless the user has specified a custom browser support policy.
* **Custom