Beginning with EdgeHTML 15 in the Windows 10 Creators Update, Microsoft Edge introduces support for CSS Custom Properties, a new primitive value type to fully cascade variables across CSS properties. You can preview CSS Custom Properties in Windows Insider Preview builds beginning with EdgeHTML 15.15061. Check out our Custom Properties Pooch demo to see them in action! Check out our Custom Propert
![CSS Custom Properties in Microsoft Edge](https://cdn-ak-scissors.b.st-hatena.com/image/square/4ceaa311786a3c0dc7ea2e4972fea8477a33f567/height=288;version=1;width=512/https%3A%2F%2Fblogs.windows.com%2Fwp-content%2Fuploads%2Fprod%2Fsites%2F33%2F2017%2F03%2Fpooch.png)