Priority

The principles of inheritance and overriding apply to style rules. This allows you to write default rules for all model objects of a certain type and then to refine the customization with more specific rules that apply to subsets of these model objects.
The priority of a style rule depends on how specific it is and on the order with respect to other style rules of the same specificity. In general, a rule with more components in its selector has a higher priority because it is more specific. Note that a more specific rule sets property values for some model objects but not for others. When the specificity of two rules is the same, the lowest rule in the tree has priority.
Different rules apply to different groups of objects, but several rules can apply to the same object. If the same property is set on one object in several rules, only the setting in the rule with the highest priority is retained; this rule overrides all the previous ones.
To style a model object, the Designer sorts all rules that match it in priority order, and then applies the settings they contain to the graphic object representing the model object.