Isolate common stylesheets

src/js/app.js

@@ -13,6 +13,12 @@ const app = {
   link: {
     icon: appIconURL,
   },
+  styleSheets: [robotoFontStyle, appStyle]
+    .map((rawSheet) => {
+      const sheet = new CSSStyleSheet();
+      sheet.replaceSync(rawSheet);
+      return sheet;
+    }),
   page: null,
   router: new Router(),
   loader: WDLoader.instance,
@@ -23,12 +29,7 @@ const app = {
       <meta name="viewport" content="${app.meta.viewport}">
     `;
     document.title = app.title;
-    document.adoptedStyleSheets = [robotoFontStyle, appStyle]
+    document.adoptedStyleSheets = app.styleSheets;
-        .map((rawSheet) => {
-          const sheet = new CSSStyleSheet();
-          sheet.replaceSync(rawSheet);
-          return sheet;
-        });
   },
 };
 

src/js/home-page.js

@@ -26,7 +26,7 @@ class HomePage {
   #addPageStyle() {
     const sheet = new CSSStyleSheet();
     sheet.replaceSync(pageStyle);
-    document.adoptedStyleSheets = [...document.adoptedStyleSheets, sheet];
+    document.adoptedStyleSheets = [...app.styleSheets, sheet];
   }
 
   /**

src/js/routes-page.js

@@ -26,7 +26,7 @@ class RoutesPage {
   #addPageStyle() {
     const sheet = new CSSStyleSheet();
     sheet.replaceSync(pageStyle);
-    document.adoptedStyleSheets = [...document.adoptedStyleSheets, sheet];
+    document.adoptedStyleSheets = [...app.styleSheets, sheet];
   }
 
   /**