CSS if() Polyfill - Media Query Tracking Demo
What's happening here?
This page demonstrates the enhanced CSS if() polyfill with
media query tracking. The polyfill now automatically listens
for media query changes and updates styles in real-time.
Try this: Resize your browser window to be
wider or narrower than 768px. Notice how the box below changes
color, border, and font size automatically!
Responsive Box
This box changes its appearance based on the viewport width:
-
Wide screens (≥768px): Light blue
background, dark blue text and border, larger font
-
Narrow screens (<768px): Light coral
background, dark red text and border, smaller font
The polyfill automatically detects media query changes and
updates the styles without any JavaScript intervention!
How it works
The polyfill:
-
Processes CSS with
if(media(...)) conditions
-
Registers MediaQueryList listeners for each media query
-
Automatically re-evaluates and updates styles when media
queries change
-
Cleans up listeners when needed to prevent memory leaks