So I have this code in OnInspectorGUI:
GUIStyle left_aligned = new GUIStyle(EditorStyles.label) { alignment = TextAnchor.MiddleLeft };
GUILayout.BeginHorizontal();
GUILayout.Label(first_label, left_aligned);
GUILayout.Label(second_label, left_aligned);
GUILayout.EndHorizontal();
and this result:

How to make labels left aligned and get rid of space between them?
Thanks,
S.