fix(core): fix public share download icon color and theme filter scope

Signed-off-by: Peter Ringelmann <peter.ringelmann@nextcloud.com>

Author: pringelmann

core/src/views/PublicPageMenu.vue

@@ -135,7 +135,23 @@ function openDialogIfNeeded() {
 	}
 
 	&__primary-icon {
-		filter: var(--primary-invert-if-bright);
+		// Light mode: icon is black by default, invert to white when primary is dark
+		filter: var(--primary-invert-if-dark);
+
+		// Dark mode: icon is white (swapped in icons.css), invert to black when primary is bright
+		@media (prefers-color-scheme: dark) {
+			filter: var(--primary-invert-if-bright);
+		}
 	}
 }
+
+// Dark theme via Nextcloud setting (data-themes attribute, not media query)
+:global([data-themes*=dark] .public-page-menu__primary-icon) {
+	filter: var(--primary-invert-if-bright);
+}
+
+// Light theme explicitly set (overrides dark media query if system is dark but user chose light)
+:global([data-themes*=light] .public-page-menu__primary-icon) {
+	filter: var(--primary-invert-if-dark);
+}
 </style>