Guaranteed-invalid value

In CSS the guaranteed-invalid value is {{CSSXref("initial")}}.

When a custom property's value is the guaranteed-invalid value, the {{CSSXref("var")}} function cannot use it for substitution. Attempting to do so makes the declaration invalid at computed-value time, unless a valid fallback is specified.

See also

• CSS {{CSSXref("initial")}}
• CSS {{CSSXref("var")}}
• CSS Custom Properties for Cascading Variables Module Level 1 specification