diff --git a/devshells/default.nix b/devshells/default.nix
index 8223170..9e9a8f4 100644
--- a/devshells/default.nix
+++ b/devshells/default.nix
@@ -1,4 +1,5 @@
 args: {
   visonum = import ./visonum.nix args;
+  rwtw = import ./rwtw.nix args;
 }
 
diff --git a/devshells/rwtw.nix b/devshells/rwtw.nix
new file mode 100644
index 0000000..772c0f1
--- /dev/null
+++ b/devshells/rwtw.nix
@@ -0,0 +1,9 @@
+# Shell containing the tools I most commonly use for work
+{ pkgs, inputs, ... }:
+let
+  pythonDeps = ps: with ps; [ python-slugify rtoml ];
+  zolaObsidianPython = pkgs.python3.withPackages pythonDeps;
+in
+pkgs.mkShell {
+  nativeBuildInputs = with pkgs; [ zolaObsidianPython pkgs.zola cargo rustup ];
+}
diff --git a/devshells/visonum.nix b/devshells/visonum.nix
index 6441817..a5c22a8 100644
--- a/devshells/visonum.nix
+++ b/devshells/visonum.nix
@@ -1,5 +1,5 @@
 # Shell containing the tools I most commonly use for work
-{ pkgs, upkgs, inputs }:
+{ pkgs, upkgs, inputs, ... }:
 pkgs.mkShell {
   # REASON: purescript 0.15.7 and it's associated spago
   nativeBuildInputs = [ upkgs.purescript upkgs.spago pkgs.typescript pkgs.nodejs ];
diff --git a/dotfiles/neovim/lazy-lock.json b/dotfiles/neovim/lazy-lock.json
index e08c9c9..d4e1352 100644
--- a/dotfiles/neovim/lazy-lock.json
+++ b/dotfiles/neovim/lazy-lock.json
@@ -48,7 +48,7 @@
   "nvim-comment": { "branch": "main", "commit": "e9ac16ab056695cad6461173693069ec070d2b23" },
   "nvim-lspconfig": { "branch": "master", "commit": "eddaef928c1e1dd79a96f5db45f2fd7f2efe7ea0" },
   "nvim-tree.lua": { "branch": "master", "commit": "0db85a70248f9a90e61af5cdbafe5d9f4320f719" },
-  "nvim-treesitter": { "branch": "master", "commit": "831f37635df26864a397a5e35450eec97bfe60cd" },
+  "nvim-treesitter": { "branch": "master", "commit": "e2cf8977fda35ad666d7b431b0254d8da710968a" },
   "nvim-treesitter-textobjects": { "branch": "master", "commit": "8673926519ea61069f9c1366d1ad1949316d250e" },
   "nvim-web-devicons": { "branch": "master", "commit": "4ec26d67d419c12a4abaea02f1b6c57b40c08d7e" },
   "nvim_context_vt": { "branch": "master", "commit": "e592a9142fbfe0878ce886cd0d745963604c61d2" },
diff --git a/home/adrielus/features/desktop/common/firefox.nix b/home/adrielus/features/desktop/common/firefox/default.nix
similarity index 95%
rename from home/adrielus/features/desktop/common/firefox.nix
rename to home/adrielus/features/desktop/common/firefox/default.nix
index 4ee2965..5286056 100644
--- a/home/adrielus/features/desktop/common/firefox.nix
+++ b/home/adrielus/features/desktop/common/firefox/default.nix
@@ -15,6 +15,9 @@
 
       # Set default search engine
       search.default = "Google";
+
+      # Set styles applied to every website
+      userContent = builtins.readFile ./userContent.css;
       # }}}
       # {{{ Extensions
       extensions = with inputs.firefox-addons.packages.${pkgs.system}; [
@@ -142,6 +145,12 @@
       settings = {
         # Required for figma to be able to export to svg
         "dom.events.asyncClipboard.clipboardItem" = true;
+
+        # Customize css
+        "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
+
+        # Set language to english
+        "general.useragent.locale" = "en-GB";
       };
       # }}}
     };
diff --git a/home/adrielus/features/desktop/common/icons/asana.png b/home/adrielus/features/desktop/common/firefox/icons/asana.png
similarity index 100%
rename from home/adrielus/features/desktop/common/icons/asana.png
rename to home/adrielus/features/desktop/common/firefox/icons/asana.png
diff --git a/home/adrielus/features/desktop/common/icons/clockodo.png b/home/adrielus/features/desktop/common/firefox/icons/clockodo.png
similarity index 100%
rename from home/adrielus/features/desktop/common/icons/clockodo.png
rename to home/adrielus/features/desktop/common/firefox/icons/clockodo.png
diff --git a/home/adrielus/features/desktop/common/icons/desmos.png b/home/adrielus/features/desktop/common/firefox/icons/desmos.png
similarity index 100%
rename from home/adrielus/features/desktop/common/icons/desmos.png
rename to home/adrielus/features/desktop/common/firefox/icons/desmos.png
diff --git a/home/adrielus/features/desktop/common/icons/gitlab.png b/home/adrielus/features/desktop/common/firefox/icons/gitlab.png
similarity index 100%
rename from home/adrielus/features/desktop/common/icons/gitlab.png
rename to home/adrielus/features/desktop/common/firefox/icons/gitlab.png
diff --git a/home/adrielus/features/desktop/common/firefox/userContent.css b/home/adrielus/features/desktop/common/firefox/userContent.css
new file mode 100644
index 0000000..e2b4691
--- /dev/null
+++ b/home/adrielus/features/desktop/common/firefox/userContent.css
@@ -0,0 +1,5 @@
+/* add '[pdf]' next to links to PDF files */
+a[href$=".pdf"]:after {
+    font-size: smaller;
+    content: " [pdf]";
+}
diff --git a/home/adrielus/tethys.nix b/home/adrielus/tethys.nix
index bf12717..f6787c1 100644
--- a/home/adrielus/tethys.nix
+++ b/home/adrielus/tethys.nix
@@ -6,7 +6,7 @@
     ./features/desktop/common/signal.nix
     ./features/desktop/common/qbittorrent.nix
     ./features/desktop/common/zathura.nix
-    ./features/desktop/common/firefox.nix
+    ./features/desktop/common/firefox
     ./features/games
   ];