diff --git a/src/style.css b/src/style.css
index 8493d94..ab86a87 100644
--- a/src/style.css
+++ b/src/style.css
@@ -6,10 +6,11 @@
 
 html { height: 100%; width: 100%; padding: 0; margin: 0; }
 body { height: 100%; width: 100%; padding: 0; margin: 0; }
-#map { position: absolute; top: 0; bottom: 0; right: 0; left: 0; }
+/* isolation: isolate keeps mix-blend-mode contained to the map's own stacking context. */
+#map { position: absolute; top: 0; bottom: 0; right: 0; left: 0; isolation: isolate; }
 
-/* Per-tile multiply — a container-level blend can isolate under .leaflet-tile-container's translate3d. */
-.hillshade-blend img.leaflet-tile { mix-blend-mode: multiply; }
+/* Blend at the layer container so multiply composites against the base-layer sibling below. */
+.hillshade-blend { mix-blend-mode: multiply; }
 
 /* Icon state classes for GPS accuracy filter visual feedback */
 #disabled {