十字光标改成黑线

src/index.js

@@ -355,7 +355,7 @@ export default class StockHeatmap extends React.Component {
     context.lineTo(x, this.defaults.hmHeight());
     context.moveTo(30, y);
     context.lineTo(this.defaults.hmWidth(), y);
-    context.strokeStyle = '#fff';
+    context.strokeStyle = '#000';
     context.stroke();
   }