Try link and focus styles

editor-style.css

@@ -0,0 +1,8 @@
+/*
+ * Link styles
+ * https://github.com/WordPress/gutenberg/issues/42319
+ */
+a {
+	text-decoration-thickness: 1px !important;
+	text-underline-offset: .1em;
+}

functions.php

@@ -7,3 +7,24 @@
  * @package Twenty Twenty-Five
  * @since Twenty Twenty-Five 1.0
  */
+
+/**
+ * Enqueue stylesheet.css in the editors.
+ */
+function twenty_twenty_five_editor_style() {
+	add_editor_style( get_parent_theme_file_uri( 'editor-style.css' ) );
+}
+add_action( 'after_setup_theme', 'twenty_twenty_five_editor_style' );
+
+/**
+ * Enqueue stylesheet.css on the front.
+ */
+function twenty_twenty_five_enqueue_styles() {
+	wp_enqueue_style(
+		'twenty-twenty-five-style',
+		get_parent_theme_file_uri( 'style.css' ),
+		array(),
+		wp_get_theme()->get( 'Version' ),
+	);
+}
+add_action( 'wp_enqueue_scripts', 'twenty_twenty_five_enqueue_styles' );

style.css

@@ -13,3 +13,18 @@ License URI: http://www.gnu.org/licenses/gpl-2.0.html
 Text Domain: twentytwentyfive
 Tags: one-column, custom-colors, custom-menu, custom-logo, editor-style, featured-images, full-site-editing, block-patterns, rtl-language-support, sticky-post, threaded-comments, translation-ready, wide-blocks, block-styles, style-variations, accessibility-ready, blog, portfolio, news
 */
+
+/*
+ * Link styles
+ * https://github.com/WordPress/gutenberg/issues/42319
+ */
+a {
+	text-decoration-thickness: 1px !important;
+	text-underline-offset: .1em;
+}
+
+/* Focus styles */
+:where(.wp-site-blocks *:focus) {
+	outline-width: 2px;
+	outline-style: solid;
+}