Make resizers lighter; make chevron smaller; hide ellipsis when panes are collapsed.

services/web/public/stylesheets/app/editor.less

@@ -320,6 +320,9 @@
 		background-image: linear-gradient(90deg, 
 			@editor-resizer-bg-color,
 			@editor-resizer-bg-color);
+		&::after {
+			content: none;
+		}
 	}
 
 	&::before,
@@ -370,7 +373,7 @@
 	top: 50%;
 	z-index: 6;
 	background-color: @editor-toggler-bg-color;
-	
+
 	&:hover,
 	&:focus {
 		outline: none;
@@ -391,7 +394,7 @@
     	font-family: FontAwesome;
     	-webkit-font-smoothing: antialiased;
 		-moz-osx-font-smoothing: grayscale;
-    	font-size: 75%;
+    	font-size: 65%;
     	font-weight: bold;
 		color: #FFF;
 		user-select: none;

services/web/public/stylesheets/core/ol-variables.less

@@ -227,7 +227,7 @@
 @file-tree-droppable-bg-color   : tint(@ol-green, 5%);
 
 // Editor resizers
-@editor-resizer-bg-color          : @ol-blue-gray-6;
+@editor-resizer-bg-color          : @ol-blue-gray-5;
 @editor-resizer-bg-color-dragging : transparent;
 @editor-toggler-bg-color          : darken(@ol-blue-gray-2, 15%);
 @editor-toggler-hover-bg-color    : @ol-green;