feat: add stylix theme

Break Changes:
- May need reconfigure fcitx5 input method

system/modules/stylix.nix

@@ -0,0 +1,72 @@
+{
+  pkgs,
+  config,
+  username,
+  ...
+}:
+let
+  caskaydia = {
+    name = "CaskaydiaCove Nerd Font Mono";
+    package = pkgs.nerd-fonts.caskaydia-cove;
+  };
+
+  sf-pro-display-bold = pkgs.callPackage ../../pkgs/fonts/sf-pro-display-bold { };
+in
+{
+  stylix = {
+    enable = true;
+    base16Scheme = "${pkgs.base16-schemes}/share/themes/gruvbox-material-dark-medium.yaml";
+    polarity = "dark";
+
+    fonts = {
+      serif = config.stylix.fonts.monospace;
+
+      sansSerif = config.stylix.fonts.monospace;
+
+      monospace = caskaydia;
+
+      emoji = {
+        package = pkgs.noto-fonts-emoji;
+        name = "Noto Color Emoji";
+      };
+
+      sizes = {
+        terminal = 15;
+        desktop = 15;
+        popups = 12;
+      };
+    };
+  };
+
+  fonts = {
+    packages = (
+      with pkgs;
+      [
+        font-awesome
+        jetbrains-mono
+        noto-fonts-cjk-sans
+        noto-fonts-cjk-serif
+        noto-fonts-emoji
+        sf-pro-display-bold
+      ]
+    );
+
+    fontDir.enable = true;
+  };
+
+  home-manager.users."${username}" = {
+    stylix.targets.neovim.transparentBackground = {
+      main = true;
+      numberLine = true;
+      signColumn = true;
+    };
+    stylix.targets = {
+      swaync.enable = false;
+      zen-browser.enable = false;
+      waybar.enable = false;
+      hyprlock.enable = false;
+      hyprland.enable = false;
+      rofi.enable = false;
+    };
+  };
+}