Update app.py

app.py

@@ -68,8 +68,9 @@ def predict(pre_op_sphere, pre_op_cylinder, pre_op_axis):
     return f"Predicted Laser Prescription:\nSphere: {predicted_sphere:.2f}\nCylinder: {predicted_cylinder:.2f}\nAxis: {predicted_axis:.2f}"
 
 css = """
-body {
-    background-color: #131517;
+:root {
+    --bg: #131517;
+    --bg-dark: #131517;
 }
 """