diff --git a/Firefox/README.md b/Firefox/README.md
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+++ b/Firefox/README.md
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+I believe the userChrome CSS for the Tree Style Tabs addon comes from the Github wiki for the addon itself, but I'm genuinely not quite sure atm. Will definitely have to double-check later
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diff --git a/Firefox/chrome/userChrome files/TST.css b/Firefox/chrome/userChrome files/TST.css
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+#main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar > .toolbar-items {
+  opacity: 0;
+  pointer-events: none;
+}
+#main-window:not([tabsintitlebar="true"]) #TabsToolbar {
+    visibility: collapse !important;
+}
+
+#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] #sidebar-header {
+  display: none;
+}
+
+/* TST 2.4.17 - Fix for #1822 - Fix for Photon themed new tab favicon */
+#tabbar tab-item:not(.loading) tab-favicon .favicon-image[src^="moz-extension://"][src$="/resources/icons/globe-16.svg"] {
+  display: none;
+}
+#tabbar tab-item:not(.loading) tab-favicon .favicon-image[src^="moz-extension://"][src$="/resources/icons/globe-16.svg"] ~ .favicon-default::before {
+  display: inline-block !important;
+
+  background: url("chrome://branding/content/icon32.png") no-repeat center / 100% !important;
+  mask: none !important;
+}
+#tabbar tab-item:not(.loading)[data-current-uri="about:privatebrowsing"] tab-favicon .favicon-image[src^="moz-extension://"][src$="/resources/icons/globe-16.svg"] ~ .favicon-default::before {
+  background: url("chrome://browser/skin/privatebrowsing/favicon.svg") no-repeat center / 100% !important;
+}
+
+/* TST 2.4.17 - Fix for #1822 - Fix for Photon themed default favicon */
+tab-item:not(.group-tab):not([data-current-uri^="chrome:"]):not([data-current-uri^="about:addons"]):not([data-current-uri^="about:preferences"]) 
+tab-favicon .favicon-default::before {
+  background: url("/sidebar/styles/icons/moon.svg") no-repeat center / 100% !important;
+  mask: none !important;
+}
+
+#tabbar:not(.overflow) .after-tabs {
+  display: none;
+}
+#tabbar:not(.overflow) ~ .after-tabs {
+  display: block;
+}