The Styles Layout window manages the Styles of your site and Style libraries.
The window contains Styles Library, Site Styles, and Style Preview panes.
Styles Library section consists of the style library selection combo box and the selected library styles list.
Site Styles section lists all styles being in use for the current site project.
Right-clicking in the Site Styles section, you can create New Style, Rename Style, Delete Style, and Add Style to Library which adds the selected style to the current library.
Right-clicking in the Styles Library section, you can Create Library, Delete Library, Delete Style, and Insert Style which adds the selected style from the library to the site styles.
Style Preview pane displays the sample elements of the site, i.e. how they will look on pages. You can double-click an element and edit its properties.
For site styles you can select an element in the preview, copy it, then select another site style and paste in there.