diff --git a/userContent.css b/userContent.css
index 47fd77f..00f45cc 100644
--- a/userContent.css
+++ b/userContent.css
@@ -749,5 +749,112 @@
         stroke: var(--in-content-text-color)  !important;
       }
     }
+
+  /*= Fully Dark Mode - Support.org ==========================================*/
+    @-moz-document url-prefix("https://support.mozilla.org") {
+      /* Basic */
+      :root {
+        --color-blue-06: var(--in-content-link-color) !important;
+        --color-blue-07: var(--in-content-link-color-hover)  !important;
+
+        --page-bg: var(--in-content-page-background) !important;
+        --color-white: var(--in-content-page-background) !important;
+        --color-shade-bg: var(--in-content-page-background) !important;
+        --color-marketing-gray-02: var(--card-outline-color) !important;
+        --color-inverse-bg: var(--in-content-page-color) !important;
+        --color-inverse: var(--in-content-page-background) !important;
+        --color-text: var(--in-content-page-color) !important;
+        --color-text-light: var(--in-content-deemphasized-text) !important;
+        --color-link: var(--in-content-link-color) !important;
+        --color-success: var(--green-60) !important;
+        --color-warning: var(--yellow-60) !important;
+        --color-error: var(--red-60) !important;
+        --color-error-hover: var(--red-50) !important;
+        --color-moz-heading: #fff;
+        --color-moz-inverse-bg: var(red) !important;
+        --focus-shadow: 0 0 0 4px color-mix(in srgb, var(--in-content-primary-button-background) 30%, transparent),0 0 0 2px var(--in-content-primary-button-background-active);
+      }
+      body,
+      #main-content,
+      #instant-search-content,
+      #mzp-c-menu-panel-help,
+      .mzp-c-navigation {
+        color: var(--in-content-page-color) !important;
+        background: var(--in-content-page-background) !important;
+      }
+
+      /* Text */
+      .mzp-c-menu-category .mzp-c-menu-title,
+      .mzp-c-menu-item .mzp-c-menu-item-link,
+      .mzp-c-menu-item .mzp-c-menu-item-link > *,
+      .mzp-c-menu-item .mzp-c-menu-item-list a,
+      #doc-content .menu,
+      .document--content .menu,
+      .forum--entry-content .menu{
+        color: var(--in-content-page-color) !important;
+      }
+
+      .ts-select-trigger,
+      input[type="date"],
+      input[type="email"],
+      input[type="number"],
+      input[type="password"],
+      input[type="search"],
+      input[type="tel"],
+      input[type="text"],
+      input[type="time"],
+      input[type="url"],
+      select,
+      textarea,
+      #doc-content .button,
+      #doc-content .key,
+      .document--content .button,
+      .document--content .key,
+      .forum--entry-content .button,
+      .forum--entry-content .key{
+        color: var(--in-content-deemphasized-text) !important;
+      }
+
+      /* Background */
+      .sidebar-nav.topics, .sidebar-nav.topics > li {
+        background: var(--in-content-page-background) !important;
+      }
+
+      /* Fill */
+      .sumo-nav--logo,
+      .sumo-nav--search-button,
+      .sumo-nav--toggle-button,
+      .card--icon-sm,
+      .mzp-c-menu-item-icon,
+      .mzp-c-menu-button-close,
+      .topic-article--icon,
+      .card--topic > .card--icon {
+        filter: invert(95%) !important;
+      }
+
+      /* Others */
+      .sumo-button.secondary-button {
+        border-color: none !important;
+      }
+      .mzp-c-menu-panel {
+        border-color: var(--in-content-button-background-hover) !important;
+      }
+      .mzp-c-menu-item:is(:focus, :hover, :active) .mzp-c-menu-item-link .mzp-c-menu-item-title {
+        border-color: var(--in-content-page-color) !important;
+      }
+
+      @media screen and (min-width: 768px) {
+        .mzp-c-menu-panel {
+          box-shadow: box-shadow: 0 16px 16px -16px rgba(255,255,255,.3) !important;
+        }
+      }
+      .card--product,
+      .card--topic,
+      .card--article {
+        box-shadow: 0 5px 10px -3px rgba(249, 249, 250, .12) ,
+                    0 3px 16px 2px rgba(91, 91, 102, .12),
+                    0 8px 12px 1px rgba(82, 82, 94, .04) !important;
+      }
+    }
   }
 }