fix: fix formatting of options page on Fenix

CHANGELOG.md

@@ -3,6 +3,7 @@
 - Stop showing the popup for number-only matches in the name dictionary
   (e.g. 64)
   [#811](https://github.com/birchill/10ten-ja-reader/issues/811)).
+- Fix formatting of options page on Firefox for Android (Nightly).
 
 ## 1.4.8 (2021-10-21)
 

src/options/options.ts

@@ -32,6 +32,7 @@ import { startBugsnag } from '../utils/bugsnag';
 import {
   isChromium,
   isEdge,
+  isFenix,
   isFirefox,
   isMac,
   isSafari,
@@ -74,7 +75,10 @@ const config = new Config();
 
 function completeForm() {
   // UA-specific styles
-  if (isFirefox()) {
+
+  // We only add the 'firefox' class on desktop Firefox since Fenix doesn't
+  // include browser styles.
+  if (isFirefox() && !isFenix()) {
     document.documentElement.classList.add('firefox');
   }
   if (isChromium()) {

src/utils/ua-utils.ts

@@ -2,6 +2,10 @@ export function isFirefox(): boolean {
   return navigator.userAgent.indexOf('Firefox/') !== -1;
 }
 
+export function isFenix(): boolean {
+  return isFirefox() && navigator.userAgent.indexOf('Android') !== -1;
+}
+
 export function isChromium(): boolean {
   return (
     navigator.userAgent.indexOf('Chrome/') !== -1 ||