==== CSS and Layout Customization ====

This default layout can be further customized with the help of a Cascading !StyleSheet ([http://www.w3schools.com/css/ CSS]) file. The file is named {{{doc.css}}} and is placed in a {{{css}}} sub-directory under the {{{html}}} directory where the generated HTML files are located. The default CSS file is copied from the location specified in the configuration profile, which by default is {{{$T3D_HOME/css/doc.css}}}. Once changes are made to the CSS file in the output folder, they can be transfered back to the source CSS file or saved in a separate location and referenced in the documentation profile, so that the updated CSS file will be used the next time this profile is selected for the documentation of TTCN-3 test suites. Be aware that if the same output path is specified for the same input, all files will be overwritten, including any customized CSS files.

The default CSS file shall serve as a reference for customized CSS files. It is still in development and not yet complete. Comments within the file provide hints about the selectors. Further finer details can be deduced by examining the generated HTML code.

The CSS customizations are mostly for the presentation of the generated documentation. To influence the actual generated contents, the Extensible !StyleSheet Language Transformations ([http://www.w3schools.com/xsl/ XSLT]) file can be customized. It also needs to be customized shall new CSS selectors be introduced. More on XSLT in section ''The Documentation Generation Process'' below