add surface

app.py

@@ -51,6 +51,7 @@ def molecule(input_pdb):
                 let viewer = $3Dmol.createViewer(element, config);
                 viewer.addModel(pdb, "pdb");
                 viewer.getModel(0).setStyle({}, {cartoon:{color:"spectrum"}});
+                viewer.addSurface($3Dmol.SurfaceType.VDW, {opacity: 0.7, color: "lightblue"});
                 viewer.zoomTo();
                 viewer.render();
                 viewer.zoom(0.8, 2000);