docs: Mention css drop-shadow filter

We don't support this filter, currently.

diff --git a/docs/reference/gtk/css-properties.md b/docs/reference/gtk/css-properties.md
index 8fa9819fc7e56ba4320ebeedd5a3ff64a2d74b9b..809669dd90a0f699debe1ec6e3a062fe33a9bfb7 100644 (file)
--- a/docs/reference/gtk/css-properties.md
+++ b/docs/reference/gtk/css-properties.md
@@ -129,7 +129,7 @@ done with
 |:-----------|:----------|:------|
 |color       | [CSS Color Level 3](https://www.w3.org/TR/css3-color/#foreground) | |
 |opacity     | [CSS Color Level 3](https://www.w3.org/TR/css3-color/#opacity) | |
-|filter      | [CSS Filter Effect Level 1](https://drafts.fxtf.org/filters/#FilterProperty) | |
+|filter      | [CSS Filter Effect Level 1](https://drafts.fxtf.org/filters/#FilterProperty) | CSS allows drop-shadow |
 |font-family | [CSS Fonts Level 3](https://www.w3.org/TR/css3-fonts/#font-family-prop) | defaults to gtk-font-name setting |
 |font-size   | [CSS Fonts Level 3](https://www.w3.org/TR/css3-fonts/#font-size-prop) | defaults to gtk-font-name setting |
 |font-style  | [CSS Fonts Level 3](https://www.w3.org/TR/css3-fonts/#font-style-prop) | |