# Has Selector

> Use when reviewing stylesheets or components that use JavaScript to toggle classes on parent elements based on child state, form input values, or content presence — :has() may replace the JavaScript entirely.

- Skill: `thedaviddias/has-selector` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add thedaviddias/has-selector`
- Raw SKILL.md: https://api.skillmd.com/api/skills/thedaviddias/has-selector/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: thedaviddias (https://skillmd.com/u/thedaviddias)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/thedaviddias/has-selector

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# Use :has() to style parent elements based on their descendants

Before :has(), styling a parent based on its children required JavaScript: detecting state, toggling classes, and keeping DOM and styles in sync. This created coupling between styling logic and application logic. :has() moves that relationship back into CSS where it belongs, reducing JavaScript complexity, eliminating class-toggling boilerplate, and making styling intent readable in the stylesheet itself.

## Quick Reference

- :has() selects an element when a matching descendant exists inside it
- It is the parent selector CSS has needed for decades
- Baseline support since late 2023 — all major browsers include it
- Avoid complex :has() selectors in hot reflow paths — they can affect layout performance

## Check

Look for patterns in this code where JavaScript toggles a class on a parent element based on the state or content of a child element. These are candidates for replacement with :has().

## Fix

Replace the JavaScript class-toggling logic with a CSS :has() selector. Show the selector that targets the parent element when the relevant child condition is met.

## Explain

Explain how the :has() pseudo-class works, how it differs from :is() and :not(), what descendant vs child combinators mean inside :has(), and how browser support stands today.

## Code Review

Review the stylesheets and component JavaScript in this file. Flag any locations where a parent element's style is controlled by toggling a class from JavaScript based on child state — and show the equivalent :has() rule.

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For full implementation details, code examples, and framework-specific guidance,
see `references/rule.md`.

Rule page: https://frontendchecklist.io/en/rules/css/has-selector