Function compactness_css 

pub fn compactness_css() -> String

The denser-row override for the row block.

The comfortable default is block_css_declarations, which writes --row-block as ROW_BLOCK in the :root block; this emits only the compact arm, keyed on COMPACTNESS_ATTRIBUTE. Unlayered on purpose: a reader’s explicit packing choice must beat the default wherever the default was emitted.

let css = compactness_css();
assert!(css.contains("--row-block"));