Fix submenu hover issue.

packages/block-library/src/navigation-link/style.scss

@@ -220,43 +220,39 @@
 		}
 	}
 
-	// Margins in submenus.
+	// Margins in all submenus.
 	.has-child .submenu-container,
 	.has-child .wp-block-navigation-link__container {
 		.wp-block-pages-list__item,
 		.wp-block-navigation-link {
-			margin: 0 0 1em 0;
+			margin: 0;
+			padding: 0.5em 1em;
 		}
 
-		// Submenu indentation.
+		// Submenu indentation when there's no background.
 		left: -1em;
-		top: calc(100% + 1em);
+		top: 100%;
 
+		// Indentation for all submenus.
 		@include break-medium {
 			.submenu-container,
 			.wp-block-navigation-link__container {
-				left: calc(100% + 1em);
-				top: calc(-1px - 1em);
+				left: 100%;
+				top: -1px; // Border width.
 			}
 		}
 	}
 
+	// Submenu indentation when there's a background.
 	&.has-background .has-child .submenu-container,
 	&.has-background .has-child .wp-block-navigation-link__container {
-		.wp-block-pages-list__item,
-		.wp-block-navigation-link {
-			margin: 0;
-			padding: 0.5em 1em;
-		}
-
-		// Submenu indentation.
 		left: 0;
 		top: 100%;
 
+		// There's no border on submenus when there are backgrounds.
 		@include break-medium {
 			.submenu-container,
 			.wp-block-navigation-link__container {
-				left: 100%;
 				top: 0;
 			}
 		}
@@ -274,8 +270,5 @@
 		background-color: #fff;
 		color: #000;
 		border: 1px solid rgba(0, 0, 0, 0.15);
-
-		// Add some padding to menus even if the parent menu item doesn't have.
-		padding: 1em;
 	}
 }