Fix css

Signed-off-by: Kieran Fraser <Kieran.Fraser@ibm.com>

app.py

@@ -25,6 +25,11 @@ from art.attacks.poisoning.perturbations import insert_image
 device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
 
 css = """
+:root {
+  --text-md: 20px !important;
+  --text-sm: 18px !important;
+}
+.input-image { margin: auto !important }
 
 .center-text { text-align: center !important }
 .larger-gap { gap: 100px !important; }