[css-values-5] Define inherit() for custom properties #2864

Author: fantasai

css-values-5/Overview.bs

@@ -1476,6 +1476,37 @@ Custom Property References: the ''var()'' notation
 	see the CSS Custom Properties for Cascading Variables Module.
 	[[CSS-VARIABLES]]
 
+
+Inherited Value References: the ''inherit()'' notation
+
+	Like the ''inherit'' keyword, the inherit() [=functional notation=]
+	resolves to the [=computed value=] of a property on the parent.
+	Rather than resolving to the value of the same property, however,
+	it resolves to the tokenized [=computed value=]
+	of the property specified as its first argument.
+	Its second argument, if present, is used as a fallback
+	in case the first argument resolves to the [=guaranteed-invalid value=].
+
+	''inherit()'' is an [=arbitrary substitution function=]
+	whose syntax is defined as:
+
+	
+		<> = inherit( <>, <>? )
+	
+
+	To [=resolve an arbitrary substitution function|resolve an inherit() function=],
+	return the [=inherited value=] of the [=custom property=] specified by the first argument,
+	and (if specified) the fallback specified by the second argument.
+
+	Note: Future levels of CSS may allow specifying standard CSS properties in ''inherit()'';
+	however because the tokenization of [=computed values=]
+	is not fully standardized for all CSS properties,
+	this feature is deferred from Level 5.
+	Note that the [=computed value=] differs from the [=used value=],
+	and is not always the resolved value returned by {{getComputedStyle()}};
+	thus even if ''inherit(width)'' were allowed,
+	it would frequently return the keyword ''width/auto'', not the used <>.
+
  commit commentsComments0 (0)  {"resolvedServerColorMode":"day"}





  



    
  

  

          
  Footer

  


  
    
      
        
    


      
        © 2025 GitHub, Inc.
      
    

    
      Footer navigation

      

          
            Terms
          

          
            Privacy
          

          
            Security
          

          
            Status
          

          
            Docs
          

          
            Contact
          

          
  
    
       Manage cookies
    
  



  
    
      Do not share my personal information
    
  


      
    
  




    



  
    
    

    
      
    

    
    You can’t perform that action at this time.