layer() CSS functionThe layer() CSS function is used along with the @import at-rule to put the imported resource in a separate named cascade layer.
@import url layer(layer-name);
@import "dark.css" layer(framework.themes.dark);The framework.themes.dark is the layer into which the CSS file would be imported.
layer() =
layer( <layer-name> )
<layer-name> =
<ident> [ '.' <ident> ]*