diff --git a/content/standalone_image_page_mods.css b/content/standalone_image_page_mods.css
index 5c430e7..73999b4 100644
--- a/content/standalone_image_page_mods.css
+++ b/content/standalone_image_page_mods.css
@@ -1,23 +1,21 @@
 /* Source file https://github.com/MrOtherGuy/firefox-csshacks/tree/master/content/standalone_image_page_mods.css made available under Mozilla Public License v. 2.0
 See the above repository for updates as well as full license text. */
 
-/* Match *most* images urls, good enough for 99% of uses probably */
-@-moz-document regexp("(.*\.(apng|png|jpg|jpeg|gif|webp|avif|ico|bmp|APNG|PNG|JPG|JPEG|GIF|WEBP|AVIF|ICO|BMP)([\?#].*)*$)|(^data:image/.*)"){
-
+@-moz-document media-document(image){
   @media not print {
-    /* set solid color background */
-    html{ background-color: #232325 !important; }
-
-    /* remove default background */
-    body{ background-image: none !important; }
     
-    /* Position of the image, auto = default */
-    img:only-child{
-      margin: auto !important /* auto = center, 0 = top-left */
+    :root{
+      background-color: #232325 !important; /* set solid color background */
+      background-image: none !important; /* remove default background */
+    }
+    
+    /* Position of the image, auto = center (default), 0 = top-left */
+    img{
+      margin: auto !important;
     }
     
     /* Checkerboard pattern for transparent images, slight blue hue */
-    img.transparent:only-child{
+    img.transparent{
       background: conic-gradient(#eef 0.25turn, #bbc 0.25turn 0.5turn, #eef 0.5turn 0.75turn, #bbc 0.75turn) top left / 24px 24px repeat !important;
     }
   }