Button: Align link variant underline with Link and ExternalLink (WordPress#77842)

* Button: Align link variant underline with Link and ExternalLink

Apply `text-underline-offset: 0.2em` and `text-decoration-thickness: from-font` to the `is-link` variant so it visually matches the `Link` and `ExternalLink` components.

Made-with: Cursor

* Components: Add changelog entry for Button link variant underline alignment

Made-with: Cursor


---

Co-authored-by: jameskoster <jameskoster@git.wordpress.org>
Co-authored-by: ciampo <mciampini@git.wordpress.org>

Author: jameskoster

packages/components/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Enhancements
+
+-   `Button`: Align `link` variant underline (offset and thickness) with `ExternalLink` and `Link` from `@wordpress/ui` ([#77842](https://github.com/WordPress/gutenberg/pull/77842)).
+
 ### Bug Fixes
 
 -   `TabPanel`: Fix tab indicator animation while switching tabs ([#77812](https://github.com/WordPress/gutenberg/pull/77812)).

packages/components/src/button/style.scss

@@ -252,6 +252,8 @@
 		font-weight: $font-weight-regular;
 		color: $components-color-accent;
 		text-decoration: underline;
+		text-underline-offset: 0.2em;
+		text-decoration-thickness: from-font;
 
 		@media not (prefers-reduced-motion) {
 			transition-property: border, background, color;