fix all tests

tests/style/test_html_style.py

@@ -48,6 +48,7 @@ class TestStyleObjects(unittest.TestCase):
         self.assertEqual(Alignment.TOP.value, "top")
         self.assertEqual(Alignment.BOTTOM.value, "bottom")
         self.assertEqual(Alignment.JUSTIFY.value, "justify")
+        self.assertEqual(Alignment.MIDDLE.value, "middle")
     
     def test_font_initialization_defaults(self):
         """Test Font initialization with default values."""