Use system theme by default (even without Pro!)

Author: pimterry

src/index.html

@@ -70,7 +70,12 @@
     </div>
 
     <script>
-        const bgColor = localStorage.getItem('theme-background-color') || '#e4e8ed';
+        const bgColor = localStorage.getItem('theme-background-color') || (
+            // Use dark/light theme containerBackground
+            window.matchMedia("(prefers-color-scheme: dark)")
+                ? '#1e2028'
+                : '#e4e8ed'
+        );
         document.querySelector('html').style.backgroundColor = bgColor;
 
         let progressElement = document.getElementById('progress-logo');

src/model/ui/ui-store.ts

@@ -117,7 +117,7 @@ export class UiStore {
         // closed), but don't get reset when the app starts with stale account data.
         observe(this.accountStore, 'accountDataLastUpdated', () => {
             if (!this.accountStore.isPaidUser) {
-                this.setTheme('light');
+                this.setTheme('automatic');
             }
         });