refactor(stlyes): use react-flow__container helper

src/container/Viewport/index.tsx

@@ -0,0 +1,25 @@
+import React, { ReactNode } from 'react';
+
+import { useStore } from '../../store';
+import { ReactFlowState } from '../../types';
+
+const selector = (s: ReactFlowState) => s.transform;
+
+type ViewportProps = {
+  children: ReactNode;
+};
+
+function Viewport({ children }: ViewportProps) {
+  const transform = useStore(selector);
+
+  return (
+    <div
+      className="react-flow__viewport react-flow__container"
+      style={{ transform: `translate(${transform[0]}px,${transform[1]}px) scale(${transform[2]})` }}
+    >
+      {children}
+    </div>
+  );
+}
+
+export default Viewport;