A cascaded value is the single value selected for a particular CSS property on an element after the cascade resolves competing declarations. Each property has at most one cascaded value; if no declaration applies, it has none. Source order decides between declarations with equal specificity, so later rules win. section 1.1.4
Cascade and inheritance are related but distinct. When an element has no cascaded value, it may inherit one from an ancestor; inherited text properties such as color and font-family flow down the DOM until a cascaded value overrides them. The inherit keyword deliberately selects the parent’s value, keeping a footer link aligned with its surrounding text. section 1.2 section 1.3.1
Progressive enhancement through fallback
Declare a broadly supported color first, then a newer transparent form: the browser that understands both uses the later declaration as the cascaded value; an older browser ignores the unknown declaration and keeps the usable fallback. section 1.5.1
aside {
background-color: #333333; #1
background-color: #333333aa; #2
}
Shows fallback declarations whose final cascaded value depends on browser support. section 1.5.1
