In order to fit the design of your website perfectly, the FSI Viewer and FSI Pages skin can easily be customized to your liking via CSS. The tutorial Creating custom skins for FSI Viewer shows you the basic structure of the CSS file with an example custom skin. This tutorial explains how to change the skin in a more advanced way by overruling core CSS rules, with the example of changing the FSI Viewer logo to a custom logo.
CSS rules, which define the general appearance and are valid on an overall level, are defined in the corresponding core CSS files, which can be found in /fsi/web/viewer/skins/resources – For FSI Viewer, fsi-core.css and fsi-viewer-core.css apply, for FSI Pages, fsi-core.css and fsi-pages-core.css apply.
The core CSS files will also be loaded before the skin which is defined via the parameter skin – so all changes made in the custom skin CSS overrule the core CSS rules.
IMPORTANT: Never change the classes of the core CSS files. If you would like to adapt the CSS rules listed there, please overwrite them in a custom skin file or in the HTML document instead.