diff --git a/neovim/default.nix b/neovim/default.nix
index c06ccb7..126cdf7 100644
--- a/neovim/default.nix
+++ b/neovim/default.nix
@@ -38,6 +38,7 @@
         nvim-treesitter-textobjects
         nvim-ts-context-commentstring
         markdown-preview-nvim # use({ "iamcco/markdown-preview.nvim", run = ":call mkdp#util#install()" })
+        render-markdown-nvim
         toggleterm-nvim
         nvim-notify
         comment-nvim
@@ -177,7 +178,17 @@
 
         require("local_firenvim")
 
-        require("CopilotChat").setup()
+        require("CopilotChat").setup({
+          highlight_headers = false,
+          separator = "---",
+          error_header = "> [!ERROR] Error",
+          window = {
+            layout = "float",
+            width = 0.8,
+            height = 0.8,
+          },
+        })
+
         require("diffview").setup({
           view = {
             merge_tool = {
@@ -186,6 +197,10 @@
             }
           }
         })
+
+        require("render-markdown").setup({
+          file_types = { "markdown", "vimwiki", "copilot-chat" },
+        })
       '';
     };
   };
diff --git a/neovim/keymaps.lua b/neovim/keymaps.lua
index 2179b03..5ece7b2 100644
--- a/neovim/keymaps.lua
+++ b/neovim/keymaps.lua
@@ -67,3 +67,6 @@ vim.cmd('nnoremap <expr> * v:hlsearch ? ":nohlsearch<cr>" : "*"')
 
 -- insert-map jj/jk to escape
 require("better_escape").setup()
+
+-- open Copilot Chat window
+nnoremap("<leader>cc", ":lua require('CopilotChat').open()<CR>")