Kilotest: Diagnoses of CSS invalid violation by HTML element 0 on Institute for Progress page

Basics

About the Institute for Progress page

URL: https://ifp.org/
Tested 28 days ago by job 00v on 2026-05-04 at 17:00

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

About the CSS invalid issue

Why it matters: Document cannot be properly displayed
Priority: high
Related WCAG standard: 4.1

Diagnoses

Here is how tools diagnose the CSS invalid issue for HTML element 0 of the Institute for Progress page.

CSS: contain-intrinsic-size: Property contain-intrinsic-size doesn't exist.
Tool: Html Checker API (World Wide Web Consortium)