diff --git a/_config.yml b/_config.yml
index 76e5f65..dcf0097 100644
--- a/_config.yml
+++ b/_config.yml
@@ -54,8 +54,7 @@ favicon:
   medium: /images/favicon-32x32-next.png
   apple_touch_icon: /images/apple-touch-icon-next.png
   safari_pinned_tab: /images/logo.svg
-  #android_manifest: /images/manifest.json
-  #ms_browserconfig: /images/browserconfig.xml
+  #android_manifest: /manifest.json
 
 # Custom Logo (Warning: Do not support scheme Mist)
 custom_logo: #/uploads/custom-logo.jpg
diff --git a/layout/_partials/head/head.njk b/layout/_partials/head/head.njk
index 6f26306..949a476 100644
--- a/layout/_partials/head/head.njk
+++ b/layout/_partials/head/head.njk
@@ -20,9 +20,6 @@
 {%- if theme.favicon.android_manifest %}
   <link rel="manifest" href="{{ url_for(theme.favicon.android_manifest) }}">
 {%- endif %}
-{%- if theme.favicon.ms_browserconfig %}
-  <meta name="msapplication-config" content="{{ url_for(theme.favicon.ms_browserconfig) }}">
-{%- endif %}
 
 {%- if theme.disable_baidu_transformation %}
   <meta http-equiv="Cache-Control" content="no-transform">
diff --git a/source/css/main.styl b/source/css/main.styl
index 8084230..4102223 100644
--- a/source/css/main.styl
+++ b/source/css/main.styl
@@ -1,4 +1,4 @@
-// CSS Style Guide: http://codeguide.co/#css
+// CSS Style Guide: https://codeguide.co/#css
 
 
 $scheme    = hexo-config('scheme') ? hexo-config('scheme') : 'Muse';
diff --git a/source/js/utils.js b/source/js/utils.js
index 8513c25..3f3cb42 100644
--- a/source/js/utils.js
+++ b/source/js/utils.js
@@ -283,10 +283,9 @@ NexT.utils = {
 
   supportsPDFs: function() {
     const ua = navigator.userAgent;
-    const isFirefoxWithPDFJS = ua.includes('irefox') && parseInt(ua.split('rv:')[1].split('.')[0], 10) > 18;
     const supportsPdfMimeType = typeof navigator.mimeTypes['application/pdf'] !== 'undefined';
     const isIOS = /iphone|ipad|ipod/i.test(ua.toLowerCase());
-    return isFirefoxWithPDFJS || (supportsPdfMimeType && !isIOS);
+    return ua.includes('irefox') || (supportsPdfMimeType && !isIOS);
   },
 
   getComputedStyle: function(element) {