surface fix

app.py

@@ -52,6 +52,7 @@ def molecule(input_pdb):
                 viewer.addModel(pdb, "pdb");
                 viewer.getModel(0).setStyle({}, {cartoon:{color:"spectrum"}});
                 viewer.addSurface($3Dmol.SurfaceType.VDW, {opacity: 0.7, color: "lightblue"});
+                viewer.addStyle({}, {surface: {opacity: 0.6, colorfunc: {color: $3Dmol.Gradient.RWB, min: -10, max: 10}}});
                 viewer.zoomTo();
                 viewer.render();
                 viewer.zoom(0.8, 2000);