Kilotest: Diagnoses of invalid at-rule
violation by HTML element 0 on Centre for Effective Altruism page
Basics
About the Centre for Effective Altruism page
- URL: https://www.effectivealtruism.org/
- Tested 38 days ago by job
6gwon 2026-04-24 at 21:54
About HTML element 0
- Tag name:
HTML - Text: [not applicable]
- Start tag:
<html lang="en"> - XPath:
/html - Bounding box: x = 0, y = 0, width = 1920, height = 8466
About the invalid at-rule
issue
- Why it matters: Document cannot be properly displayed in particular contexts
- Priority: high
- Related WCAG standard: 4.1
Diagnoses
Here is how tools diagnose the invalid at-rule
issue for HTML element 0 of the Centre for Effective Altruism page.
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)
- CSS: Unrecognized at-rule @container
Tool: Html Checker API (World Wide Web Consortium)