pinwheel: Remove rounded corners from Firefox tabs

hosts/pinwheel/modules/firefox/default.nix

@@ -66,7 +66,14 @@ let
     "network.dns.force_waiting_https_rr" = false;
     "browser.smartwindow.enabled" = false;
     "browser.smartwindow.isDefaultWindow" = false;
+    "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
   };
+
+  sharedUserChrome = ''
+    :root {
+      --tab-border-radius: 0 !important;
+    }
+  '';
 in
 {
   home-manager.users.alex = {
@@ -88,6 +95,8 @@ in
           isDefault = true;
 
           settings = sharedSettings // { };
+
+          userChrome = sharedUserChrome;
         };
 
         work = {
@@ -95,11 +104,10 @@ in
           name = "work";
 
           settings = sharedSettings // {
-            "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
             "network.lna.skip-domains" = "music-admin-staging.soundtr.ac,api-internal.apps-us.platform.staging.internal.syb.sh";
           };
 
-          userChrome = ''
+          userChrome = sharedUserChrome + ''
             .tab-content {
               border-top: solid #9400FF !important;
             }