diff --git a/README.md b/README.md
index cd898ac..b233d8d 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,7 @@ Core keymaps available globally (not plugin-specific). These provide fallbacks f
 | n | `<leader>xt` | Toggle diagnostics | Flips `vim.diagnostic.enable()` |
 | n | `<leader>gg` | Git: Changed files → quickfix | Lists all modified/deleted/untracked files with status |
 | n | `<leader>hi` | Highlight inspector | Shows highlight/capture stack under cursor |
+| n | `<leader>bg` | Toggle background (light/dark) | Switches between light and dark colorscheme modes |
 
 ### `lua/netrw-config.lua`
 
diff --git a/lua/keymaps.lua b/lua/keymaps.lua
index 7ff7d78..90bbf55 100644
--- a/lua/keymaps.lua
+++ b/lua/keymaps.lua
@@ -76,3 +76,12 @@ end, { desc = 'Git: Changed files to quickfix (with status)', silent = true })
 map('n', '<leader>hi', function()
   require('utils').show_highlight_info()
 end, { desc = 'Debug: Show highlight group and color under cursor', silent = true })
+
+-- UI: Toggle background (light/dark)
+map('n', '<leader>bg', function()
+  if vim.o.background == 'dark' then
+    vim.o.background = 'light'
+  else
+    vim.o.background = 'dark'
+  end
+end, { desc = 'UI: Toggle background (light/dark)', silent = true })