fix(ui5-side-navigation): correct styles for static area (#4526)

Fixes: #4515

Author: dimovpetar

packages/fiori/src/SideNavigation.js

@@ -10,6 +10,7 @@ import SideNavigationItemPopoverContentTemplate from "./generated/templates/Side
 
 // Styles
 import SideNavigationCss from "./generated/themes/SideNavigation.css.js";
+import SideNavigationPopoverCss from "./generated/themes/SideNavigationPopover.css.js";
 
 /**
  * @public
@@ -142,7 +143,7 @@ class SideNavigation extends UI5Element {
 	}
 
 	static get staticAreaStyles() {
-		return [SideNavigationCss];
+		return [SideNavigationPopoverCss];
 	}
 
 	static get render() {

packages/fiori/src/themes/SideNavigation.css

@@ -37,14 +37,4 @@
 .ui5-sn-spacer {
     flex: auto;
     min-height: 3rem;
-}
-
-.ui5-side-navigation-popover [ui5-li][focused]:first-child::part(native-li)::after {
-	border-top-left-radius: var(--_ui5_side_navigation_overflow_border_radius);
-	border-top-right-radius: var(--_ui5_side_navigation_overflow_border_radius);
-}
-
-.ui5-side-navigation-popover [ui5-li][focused]:last-child::part(native-li)::after {
-	border-bottom-left-radius: var(--_ui5_side_navigation_overflow_border_radius);
-	border-bottom-right-radius: var(--_ui5_side_navigation_overflow_border_radius);
-}
+}

packages/fiori/src/themes/SideNavigationPopover.css

@@ -0,0 +1,9 @@
+.ui5-side-navigation-popover [ui5-li][focused]:first-child::part(native-li)::after {
+	border-top-left-radius: var(--_ui5_side_navigation_overflow_border_radius);
+	border-top-right-radius: var(--_ui5_side_navigation_overflow_border_radius);
+}
+
+.ui5-side-navigation-popover [ui5-li][focused]:last-child::part(native-li)::after {
+	border-bottom-left-radius: var(--_ui5_side_navigation_overflow_border_radius);
+	border-bottom-right-radius: var(--_ui5_side_navigation_overflow_border_radius);
+}