Cascade layers change where the cascade compares declarations. Given equal origin and equal importance (no `!important`), at what point in the cascade-sorting algorithm is layer order consulted relative to specificity and source order?
@layer base, theme;
@layer theme { a { color: red; } } /* specificity 0,0,1 */
@layer base { #id a { color: green; } } /* specificity 1,0,1 */