Customizing HTML output
You can modify the look and feel of your HTML output by changing parameter settings
to include custom CSS, headers and footers, or table-of-contents navigation in topics .
Setting parameters for custom HTML Customizing HTML with a .properties file .properties file to reference a set of build parameters when building output with the dita command. The DITA-OT documentation uses a .properties file to include custom CSS, header branding, and table-of-contents navigation in the HTML5 output.