Custom css is supported for html export, from the docs at (https://orgmode.org/manual/CSS-support.html https://orgmode.org/manual/CSS-support.html) -- The HTML

Custom css is supported for html export, from the docs at (https://orgmode.org/manual/CSS-support.html https://orgmode.org/manual/CSS-support.html) -- The HTML export back-end includes a compact default style in each exported HTML file. To override the default style with another style, use these keywords in the Org file. They will replace the global defaults the HTML exporter uses. #+HTML_HEAD: <link rel="stylesheet" type="text/css" href="style1.css" /> #+HTML_HEAD_EXTRA: <link rel="alternate stylesheet" type="text/css" href="style2.css" /> To just turn off the default style, customize org-html-head-include-default-style variable, or use this option line in the Org file. #+OPTIONS: html-style:nil