Rework pointing / basic label for more accurate arrows

src/definitions/elements/label.less

@@ -1171,6 +1171,34 @@ a.ui.basic.label:hover {
   left: auto;
 }
 
+/* Basic Pointing */
+
+/*--- Above ---*/
+
+.ui.basic.pointing.label:before,
+.ui.basic.pointing.above.label:before {
+  top: @basicPointingTriangleOffset;
+}
+/*--- Below ---*/
+.ui.basic.pointing.bottom.label:before,
+.ui.basic.pointing.below.label:before {
+  top: auto;
+  margin-left: @basicPointingTriangleOffset;
+  bottom: @basicPointingTriangleOffset;
+}
+/*--- Left ---*/
+.ui.basic.pointing.left.label:before {
+  top: 50%;
+  margin-top: @basicPointingTriangleOffset;
+}
+/*--- Right ---*/
+.ui.basic.pointing.right.label:before {
+  top: 50%;
+  margin-top: @basicPointingTriangleOffset;
+  right: @basicPointingTriangleOffset;
+}
+
+
 /*------------------
    Floating Label
 -------------------*/

src/themes/default/elements/label.variables

@@ -218,14 +218,18 @@
 
 /* Pointing */
 @pointingBorderColor: inherit;
+@pointingBorderWidth: @borderWidth;
 @pointingVerticalDistance: 1em;
-@pointingTriangleSize: 0.6em;
+@pointingTriangleSize: 0.6666em;
 @pointingHorizontalDistance: @pointingTriangleSize;
 
-@pointingTriangleOffset: ~"calc("(-@pointingTriangleSize / 2)~" - "@borderWidth~")";
+@pointingTriangleOffset: -@pointingTriangleSize / 2;
 @pointingTriangleTransition: background @labelTransitionDuration @labelTransitionEasing;
 @pointingTriangleZIndex: 2;
 
+/* Basic Pointing */
+@basicPointingTriangleOffset: ~"calc("(-@pointingTriangleSize / 2)~" - "@pointingBorderWidth~")";
+
 /* Floating */
 @floatingTopOffset: -1em;
 @floatingLeftOffset: -1.5em;