diff --git a/tests/test_theme_nerv.py b/tests/test_theme_nerv.py
new file mode 100644
index 0000000..b2e4383
--- /dev/null
+++ b/tests/test_theme_nerv.py
@@ -0,0 +1,47 @@
+import pytest
+from unittest.mock import MagicMock
+from imgui_bundle import imgui
+from src import theme_nerv
+
+def test_apply_nerv_sets_rounding_and_colors(monkeypatch):
+ # Mock imgui on the module level to intercept calls in apply_nerv
+ mock_style = MagicMock()
+ mock_imgui = MagicMock()
+ mock_imgui.get_style.return_value = mock_style
+ # Mock ImVec4 to return its arguments as a tuple to verify values
+ mock_imgui.ImVec4.side_effect = lambda r, g, b, a=1.0: (r, g, b, a)
+ 
+ monkeypatch.setattr(theme_nerv, "imgui", mock_imgui)
+
+ # Call apply_nerv
+ theme_nerv.apply_nerv()
+
+ # Verify rounding styles (must be 0.0 for NERV theme)
+ assert mock_style.window_rounding == 0.0
+ assert mock_style.child_rounding == 0.0
+ assert mock_style.frame_rounding == 0.0
+ assert mock_style.popup_rounding == 0.0
+ assert mock_style.scrollbar_rounding == 0.0
+ assert mock_style.grab_rounding == 0.0
+ assert mock_style.tab_rounding == 0.0
+
+ # Verify borders
+ assert mock_style.window_border_size == 1.0
+ assert mock_style.frame_border_size == 1.0
+ assert mock_style.popup_border_size == 1.0
+ assert mock_style.child_border_size == 1.0
+ assert mock_style.tab_border_size == 1.0
+
+ # Verify key colors
+ # window_bg should be BLACK (0, 0, 0, 1.0)
+ # text should be NERV_ORANGE (255/255.0, 152/255.0, 48/255.0, 1.0)
+ 
+ # Extract calls to set_color_
+ # Using real imgui.Col_ values for keys because they are bound in NERV_PALETTE at import time
+ color_calls = {call[0][0]: call[0][1] for call in mock_style.set_color_.call_args_list}
+ 
+ assert imgui.Col_.window_bg in color_calls
+ assert color_calls[imgui.Col_.window_bg] == (0.0, 0.0, 0.0, 1.0)
+ 
+ assert imgui.Col_.text in color_calls
+ assert color_calls[imgui.Col_.text] == (1.0, 152/255.0, 48/255.0, 1.0)