Translate CSS selectors restructuring to es, fr, zh

[mintlify]

Translates the CSS selectors readability improvements from #5454 into Spanish, French, and Chinese.

Changes

• Replaced flat identifier/selector lists with categorized accordion sections in all three language files
• Updated description format from Name: \value`to`value` — Description` to match the new English structure
• Removed deprecated headings ("Adding style.css", "Using identifiers and selectors", "Adding custom JavaScript")
• Added new "ID selectors" and "Element selectors" subsections with categorized accordions
• Moved the breaking-changes warning inline and removed the bottom <Warning> block
• Updated frontmatter descriptions to match the English source

---

Note

Low Risk
Low risk documentation-only changes that reorganize and reword translated MDX content without affecting runtime code.

Overview
Updates the Spanish, French, and Chinese custom-scripts.mdx docs to match the new CSS selector documentation structure, splitting guidance into ID selectors vs element selectors and replacing flat lists with categorized accordions.

Refreshes frontmatter descriptions and assorted wording (including Google Analytics wording), moves the compatibility warning inline, and removes now-redundant section headings (e.g., Adding style.css / Adding custom JavaScript).

^{Reviewed by Cursor Bugbot for commit 8506949. Bugbot is set up for automated code reviews on this repo. Configure here.}

[mintlify-development]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
userauth	🟡 Building	–	Apr 20, 2026, 6:53 PM

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
mintlify	🔴 Failed	–	Apr 20, 2026, 6:57 PM