🏠 New in Low Baseline Support: sibling-count() and sibling-index()

August 18, 2026

caniuse · mdn · spec

The sibling-count() and sibling-index() CSS functions return integers that are useful to style elements based on their positions among siblings or on the number of siblings, for example as part of a calc() expression.

Source features

• css.types.sibling-count [mdn]
• css.types.sibling-index [mdn]