add 404 page

src/router/index.js

@@ -49,6 +49,11 @@ const routes = [
     name: "SettingsView",
     component: SettingsView,
   },
+  {
+    path: "/:pathMatch(.*)",
+    // alias: "*",
+    component: () => import("../views/NotFound.vue"),
+  }
 ];
 
 const router = createRouter({

src/views/NotFound.vue

@@ -0,0 +1,12 @@
+<template>
+  <div class="fof">
+    404! Page Not Found!
+  </div>
+</template>
+
+<style lang="scss">
+.fof {
+    padding: 1rem;
+    font-size: 2rem;
+}
+</style>