Canvas: Improve diagram styling

Change-Id: If1c3d48cd94b63de86c8d7ecdb40974af951367f
diff --git a/apps/canvas/front/src/App.css b/apps/canvas/front/src/App.css
index 4444564..9697204 100644
--- a/apps/canvas/front/src/App.css
+++ b/apps/canvas/front/src/App.css
@@ -1,3 +1,20 @@
+body {
+	overflow: hidden;
+}
+
+.react-flow__handle {
+	min-width: initial !important;
+	min-height: initial !important;
+	height: 4px !important;
+	width: 4px !important;
+	border: none !important;
+}
+
+.react-flow__edge-path {
+    stroke: black !important;
+ 
+}
+
 .react-flow__handle.connectingto {
 	background: #ff6060;
 }
@@ -5,7 +22,3 @@
 .react-flow__handle.valid {
 	background: #55dd99;
 }
-
-body {
-	overflow: hidden;
-}
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