diff --git a/doc/advanced/customizing-gitea.en-us.md b/doc/advanced/customizing-gitea.en-us.md
index bad6342a..4c0235c0 100644
--- a/doc/advanced/customizing-gitea.en-us.md
+++ b/doc/advanced/customizing-gitea.en-us.md
@@ -354,7 +354,7 @@ To make a custom theme available to all users:
 
 Community themes are listed in [gitea/awesome-gitea#themes](https://gitea.com/gitea/awesome-gitea#themes).
 
-The `arc-green` theme source can be found [here](https://github.com/go-gitea/gitea/blob/main/web_src/less/themes/theme-arc-green.less).
+The `arc-green` theme source can be found [here](https://github.com/go-gitea/gitea/blob/main/web_src/css/themes/theme-arc-green.css).
 
 If your custom theme is considered a dark theme, set the global css variable `--is-dark-theme` to `true`.
 This allows Gitea to adjust the Monaco code editor's theme accordingly.
diff --git a/doc/developers/guidelines-frontend.en-us.md b/doc/developers/guidelines-frontend.en-us.md
index 7f4d87d9..e801ee4c 100644
--- a/doc/developers/guidelines-frontend.en-us.md
+++ b/doc/developers/guidelines-frontend.en-us.md
@@ -21,13 +21,13 @@ menu:
 
 ## Background
 
-Gitea uses [Less CSS](https://lesscss.org), [Fomantic-UI](https://fomantic-ui.com/introduction/getting-started.html) (based on [jQuery](https://api.jquery.com)) and [Vue3](https://vuejs.org/) for its frontend.
+Gitea uses [Fomantic-UI](https://fomantic-ui.com/introduction/getting-started.html) (based on [jQuery](https://api.jquery.com)) and [Vue3](https://vuejs.org/) for its frontend.
 
 The HTML pages are rendered by [Go HTML Template](https://pkg.go.dev/html/template).
 
 The source files can be found in the following directories:
 
-* **Less styles:** `web_src/less/`
+* **CSS styles:** `web_src/css/`
 * **JavaScript files:** `web_src/js/`
 * **Vue components:** `web_src/js/components/`
 * **Go HTML templates:** `templates/`