diff --git a/frontend/src/components/Dashboard/ui/core/core.css b/frontend/src/components/Dashboard/ui/core/core.css
index f382f09..7303dbb 100644
--- a/frontend/src/components/Dashboard/ui/core/core.css
+++ b/frontend/src/components/Dashboard/ui/core/core.css
@@ -576,8 +576,9 @@
   outline-offset: 2px;
 }
 
+/* The rail comes before the input, so no sibling selector reaches it. */
 .dui-slider-input:disabled ~ .dui-slider-thumb,
-.dui-slider-input:disabled ~ .dui-slider-rail {
+.dui-slider:has(.dui-slider-input:disabled) .dui-slider-rail {
   opacity: 0.45;
 }