If CSS property value is unset, then if it is an inherited property, this is treated as inherit, and if it is not, this is treated as initial. It is like erasing all declarations. Also note that it is not supported in IE.
Here is sample code using css unset
<style type="text/css"> .box {color:green;} h2 {color: blue;} .box > h2 {color:unset;} </style> <h2>h2 text</h2> <div class="box"> <h2>h2 text with color unset (it will use inherit as color is inherited property)</h2> </div>
Specification and Browser compatibility
Specification | Status | Categories |
---|---|---|
CSS unset value | W3C Candidate Recommendation | CSS |
Chrome | Firefox | IE | Edge | Safari | Opera |
---|---|---|---|---|---|
Yes 41+ | Yes 27+ | No | Yes 13+ | Yes 9.1+ | Yes 28+ |
Android Chrome | Android Firefox | iOS Safari | IE Mobile | Opera Mobile |
---|---|---|---|---|
Yes 47+ | Yes 44+ | Yes 9.3+ | No | No |
source: caniuse.com