diff --git a/src/styles/blocks/filter-panel.css b/src/styles/blocks/filter-panel.css
index 4a5d741d..4efcc248 100644
--- a/src/styles/blocks/filter-panel.css
+++ b/src/styles/blocks/filter-panel.css
@@ -50,7 +50,8 @@
     max-height: calc(100vh - 108px);
     transition:
       transform 0.5s cubic-bezier(0.65, 0.05, 0.36, 1),
-      opacity calc(0.5s * (var(--is-filter-open)));
+      opacity 0.5s;
+    background-color: hsl(0 0% var(--lightness));
   }
 
   .filter-panel__button {