See Where Styles Are Applied In. The Styles pane displays. In the ideal MS point of view users would not use any of the formatting commands in the Home tab all formatting would be applied by styles.
And you can open up any specific attribute to find out which CSS selector and file is responsible. They are applied on top of the character formatting defined for the paragraph style. Selecting Elements With the Type Selector.
Next youll apply styles to the HTML page you created.
Then open indexhtml in your browser to see the default styles of your browser which will appear similar to the following image. Then click the Styles button in the lower-right corner of the Styles section. Selecting Elements With the Type Selector. And you can open up any specific attribute to find out which CSS selector and file is responsible.