adding fixes for the button style

Author: DenisaCG

src/widget.ts

@@ -5,6 +5,7 @@ import {
 } from '@jupyterlab/docregistry';
 import { ToolbarButton } from '@jupyterlab/apputils';
 import { IRenderMimeRegistry } from '@jupyterlab/rendermime';
+import { runIcon } from '@jupyterlab/ui-components';
 
 import { Panel } from '@lumino/widgets';
 import { Signal } from '@lumino/signaling';

style/base.css

@@ -0,0 +1,11 @@
+.jp-blockly-button:hover {
+	background-color: transparent !important;
+}
+
+.jp-blockly-runButton {
+	background-color: var(--md-green-500)
+}
+
+.jp-blockly-runButton:hover {
+	background-color: var(--md-green-700)
+}