Pin/Unpin thumbnail panel styling issue

Packages/viewerbase/client/components/basic/hidingPanel/hidingPanel.styl

@@ -1,5 +1,5 @@
 
-.hidingPanel, .hidingPanelContent, .studyBrowserContainer, .arrowIcon, .arrowIconRotate, .hidingPanelContentOpaque
+.hidingPanel, .hidingPanelContent, .studyBrowserContainer, .arrowIcon, .arrowIconRotate
 
   -o-transition: all 0.3s ease-out
   -ms-transition: all 0.3s ease-out
@@ -77,7 +77,4 @@
         color: #FFFFFF
 
       .pinInactive
-        color: #424242
-
-  .hidingPanelContentOpaque
-    opacity: 1;
+        color: #424242