WIP #216. QA mentioned that bugs remained, so we keep working on it.

src/views/Login/index.vue

@@ -105,7 +105,8 @@ export default {
   },
   created() {
     // 考慮到使用者可能在未登入的情況下貼入一個頁面網址連結過來瀏覽器
-    this.setRememberedReturnToUrl(this.$route.query['return-to']);
+    // btoa: 對字串進行 Base64 編碼
+    this.setRememberedReturnToUrl(btoa(this.$route.query['return-to']));
   },
 };
 </script>