diff --git a/core/css/styles.css b/core/css/styles.css
index 33bfd36eb0..23e2f9a96e 100644
--- a/core/css/styles.css
+++ b/core/css/styles.css
@@ -274,9 +274,9 @@ fieldset.warning a { color:#b94a48 !important; font-weight:bold; }
 	white-space:nowrap; overflow:hidden; text-overflow:ellipsis; /* ellipsize long app names */
 }
 	/* icon opacity and hover effect */
-	#navigation a { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)"; filter:alpha(opacity=50); opacity:.5; }
-	#navigation a:hover, #navigation a:focus { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=80)"; filter:alpha(opacity=80); opacity:.8; }
-	#navigation a.active { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=100)"; filter:alpha(opacity=100); opacity:1; }
+	#navigation a { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)"; filter:alpha(opacity=50); opacity:.5; } /* 50% opacity when inactive */
+	#navigation a:hover, #navigation a:focus { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=80)"; filter:alpha(opacity=80); opacity:.8; } /* 80% opacity when hovered or focused */
+	#navigation a.active { -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=100)"; filter:alpha(opacity=100); opacity:1; } /* full opacity for the active app */
 	/* positioning */
 	#navigation .icon {
 		display:block;