Add map filter css property

diff --git a/app/assets/stylesheets/common.scss b/app/assets/stylesheets/common.scss
index c5e2d14b1577a8a35e90747739616b5f56b6b672..b0b706562df7cc1ff53dbb9441a97945b8fbedd8 100644 (file)
--- a/app/assets/stylesheets/common.scss
+++ b/app/assets/stylesheets/common.scss
@@ -9,6 +9,7 @@
 
 body {
   font-size: $typeheight;
+  --dark-mode-map-filter: brightness(.8);
 }
 
 time[title] {
@@ -507,7 +508,7 @@ body.small-nav {
 @include color-mode(dark) {
   .leaflet-tile-container .leaflet-tile,
   .mapkey-table-entry td:first-child > * {
-    filter: brightness(.8);
+    filter: var(--dark-mode-map-filter);
   }
 
   .leaflet-container .leaflet-control-attribution a {