Unknown propertyUnknown Property
The CSS property name is not recognized by the browser.
CSS nesting unsupportedThe browser does not support native CSS nesting syntax.
Native CSS nesting (using & or directly nesting selectors) is a new CSS feature. Older browsers do not understand this syntax and will ignore the nested rules.
Use a CSS preprocessor (Sass, PostCSS) as a fallback. Check browser support before using native nesting. Provide flat (non-nested) CSS as a fallback.
.parent {
.child { color: red; }
}Unknown propertyThe CSS property name is not recognized by the browser.
CSS Paint API errorA CSS Paint Worklet failed to render or register.
Missing semicolonA semicolon is missing at the end of a CSS declaration.
:has() unsupportedThe browser does not support the :has() pseudo-class.
Duplicate selectorThe same selector appears multiple times in the stylesheet.
text-overflow: ellipsis not workingThe text-overflow: ellipsis property does not show an ellipsis for overflowing text.