Interface CustomAtRuleDefinition

Defines the type of body contained within the at-rule block.

• declaration-list: A CSS declaration list, as in a style rule.
• rule-list: A list of CSS rules, as supported within a non-nested at-rule such as @media or @supports.
• style-block: Both a declaration list and rule list, as accepted within a nested at-rule within a style rule (e.g. @media inside a style rule with directly nested declarations).

Defines the syntax for a custom at-rule prelude. The value should be a CSS syntax string representing the types of values that are accepted. This property may be omitted or set to null to indicate that no prelude is accepted.