/* doxygen-awesome themes h2.groupheader but not div.groupHeader, whose hard-coded white box-shadow bleeds through in dark mode. */
div.groupHeader {
    box-shadow:
         13px 0   var(--page-background-color),
        -13px 0   var(--page-background-color),
         13px 1px var(--separator-color),
        -13px 1px var(--separator-color);
    color: var(--page-foreground-color);
}