Update app.py

app.py

@@ -69,9 +69,9 @@ def predict(pre_op_sphere, pre_op_cylinder, pre_op_axis):
 
 css = """
 <style>
-body {
-    background-color: #131517 !important;
-}
+:root {
+	--bg-dark: #131517;
+}		
 </style>
 """