Kilotest: Diagnoses of invalid at-rule
violation by HTML element 0 on Institute for Progress page
Here is how tools diagnose the invalid at-rule
issue for HTML element 0 of the Institute for Progress page.
Basics
- About the
invalid at-rule
issue- Why it matters: Document cannot be properly displayed in particular contexts
- Priority: high
- Related WCAG standard: 4.1
- About the Institute for Progress page
- URL:
https://ifp.org/ - Tested on 2026-04-03 at 04:21
- URL:
- About HTML element 0
- Tag name:
HTML - Text: [not applicable]
- Start tag:
<html class="js" lang="en-US" prefix="og: https://ogp.me/ns#"> - XPath:
/html - Bounding box: x = 0, y = 0, width = 1920, height = 1080
- Tag name:
Diagnoses
- CSS: The @charset rule may only occur at the start of the style sheet. Please check that there are no spaces before it.
Tool: Html Checker API (World Wide Web Consortium)