12.6.5 CSS support

You can also give style information for the exported file. The HTML exporter assigns the following CSS classes to appropriate parts of the document - your style specifications may change these:

     .todo           TODO keywords
     .done           the DONE keyword
     .timestamp      time stamp
     .timestamp-kwd  keyword associated with a time stamp, like SCHEDULED
     .tag            tag in a headline
     .target         target for links

Each exported files contains a compact default style that defines these classes in a basic way¹. You may overwrite these settings, or add to them by using the variables org-export-html-style (for Org-wide settings) and org-export-html-style-extra (for more granular settings, like file-local settings). To set the latter variable individually for each file, you can use

     #+STYLE: <link rel="stylesheet" type="text/css" href="stylesheet.css" />

For longer style definitions, you can use several such lines. You could also directly write a <style> </style> section in this way, without referring to an external file.