Re: [csswg-drafts] [css-conditional] Should CSS.supports() accept !important in the 2nd argument? (#5692)

Thinking more about this, basically `CSS.supports(property, value)` is useful if it tells you whether `element.style.setProperty(property, value)` will work. And `setProperty` doesn't allow mixing the value and the priority, you need a third argument for that.

So `CSS.supports("background", "green !important")` should be `false` because these don't work:
```js
element.style.background = "green !important";
element.style.setProperty("background", "green !important");
```

-- 
GitHub Notification of comment by Loirooriol
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/5692#issuecomment-721440158 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config