diff --git a/CLAUDE.md b/CLAUDE.md
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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Overview
+
+This is a personal XMonad + Xmobar configuration built as a Haskell project using Nix flakes. The project uses Relude as a custom Prelude and follows a strict, opinionated Haskell development workflow.
+
+## Build System
+
+This project uses **just** for task running and **Nix flakes** for reproducible builds:
+
+```bash
+# List available commands
+just
+
+# Build the project
+just build
+
+# Run XMonad executable
+just run xmonad
+
+# Run XMobar executable
+just run xmobar
+
+# Start REPL
+just repl
+
+# Access Hoogle documentation (serves at http://127.0.0.1:8888)
+just docs
+```
+
+### Nix Commands
+
+```bash
+# Update flake inputs
+nix flake update
+
+# Build all outputs
+nix --accept-flake-config run github:juspay/omnix ci
+
+# Run without installing
+nix run .
+
+# Enter development shell (or use direnv)
+nix develop
+```
+
+### Pre-commit Hooks
+
+Pre-commit hooks are automatically configured in the Nix shell and include:
+- **fourmolu** for Haskell formatting (with FOURMOLU_DISABLE/ENABLE pragmas where needed)
+- **nixpkgs-fmt** for Nix formatting
+- **hlint** for Haskell linting
+
+Run manually: `pre-commit run -a`
+
+## Project Structure
+
+The repository follows a standard Cabal package layout:
+
+- **`src/xmonad.hs`** - Main XMonad configuration (executable entry point)
+- **`src/xmobar.hs`** - XMobar status bar configuration (executable entry point)
+- **`src/XMonadConfig/GruvboxMaterial.hs`** - Shared color scheme module providing xmobar escape codes
+
+### Two Executables
+
+The project builds two separate executables defined in `xmonad-config.cabal`:
+
+1. **xmonad** - The window manager configuration
+2. **xmobar** - The status bar configuration
+
+Both share the `XMonadConfig.GruvboxMaterial` module for consistent theming.
+
+## Architecture
+
+### XMonad Configuration (`src/xmonad.hs`)
+
+The configuration is built compositionally using function application:
+
+```haskell
+main = xmonad
+     . docks
+     . ewmhFullscreen
+     . ewmh
+     . withNavigation2DConfig def
+     . withSB myXmobar
+     $ myConfig
+```
+
+**Key architectural components:**
+
+- **Navigation2D**: Directional window and screen navigation using arrow keys and Navigation2D module
+- **Custom keybindings**: Leader-key approach (`M-a` prefix) for spawning applications and layout switching
+- **Window manipulation**: Uses `XMonad.Actions.RotSlaves` for window rotation (mimics wezterm behavior)
+- **Layout system**: Three layouts - dynamic tiling, maximised, and fullscreen
+- **StatusBar integration**: Communicates with xmobar via `_XMONAD_LOG_1` X property
+- **Mnemonic bindings**: Control (M-C) for layout manipulation, Shift (M-S) for window operations
+
+### XMobar Configuration (`src/xmobar.hs`)
+
+Defines a status bar with:
+- System information (uname, uptime, disk usage)
+- Weather data (station YPJT)
+- Date/time
+- XMonad workspace/layout information from `_XMONAD_LOG_1` property
+
+The bar is positioned statically for a multi-monitor setup (positioned at x=1920).
+
+### Color Scheme Module
+
+`XMonadConfig.GruvboxMaterial` exports color functions that wrap strings in xmobar color escape codes. This ensures consistent theming across both XMonad and XMobar configurations.
+
+## Haskell Configuration
+
+### Custom Prelude
+
+Uses **Relude** instead of standard Prelude, configured in `xmonad-config.cabal`:
+
+```cabal
+mixins:
+  base hiding (Prelude),
+  relude (Relude as Prelude, Relude.Container.One),
+  relude
+```
+
+### Default Extensions
+
+The following extensions are enabled project-wide:
+- DataKinds, DerivingStrategies, DerivingVia
+- LambdaCase, MultiWayIf, NoStarIsType
+- OverloadedStrings, StrictData, TypeFamilies, ViewPatterns
+
+### GHC Options
+
+Strict compilation with extensive warnings:
+- `-Wall`
+- `-Wincomplete-record-updates`, `-Wincomplete-uni-patterns`
+- `-Wmissing-deriving-strategies`, `-Wunused-foralls`
+- `-fprint-explicit-foralls`, `-fprint-explicit-kinds`
+
+## Development Workflow
+
+1. The project uses **haskell-flake** via flake-parts for Haskell package management
+2. HLS (Haskell Language Server) is available but checks are disabled in devShell (`hlsCheck.enable = false`)
+3. Static analysis via **stan** is enabled for the xmonad-config package
+4. The project filters `projectRoot` in `nix/modules/flake/haskell.nix` to avoid unnecessary rebuilds
+
+## Key Dependencies
+
+- **xmonad**, **xmonad-contrib** - Core window manager libraries
+- **xmobar** - Status bar library
+- **relude** - Alternative Prelude
+- **optics-core** - For lens-style accessors
+- **data-default** - Default instances for configuration
diff --git a/src/xmonad.hs b/src/xmonad.hs
index 5e5a1ec..4b5945d 100644
--- a/src/xmonad.hs
+++ b/src/xmonad.hs
@@ -99,7 +99,7 @@ myKeymap =
     , ("M-<Page_Down>", windows W.focusDown)
 
     -- window rotation
-    , ("M-C-<Page_Up>", rotAllUp)
+    , ("M-C-<Page_Up>",   rotAllUp)
     , ("M-C-<Page_Down>", rotAllDown)
 
     -- cycle workspaces
@@ -127,8 +127,8 @@ myKeymap =
     -- master pane manipulation
     , ("M-C-<Left>",  sendMessage Shrink)            -- control layout: shrink master
     , ("M-C-<Right>", sendMessage Expand)            -- control layout: expand master
-    , ("M-S-<Left>",  sendMessage (IncMasterN (-1))) -- shift windows: fewer in master
-    , ("M-S-<Right>", sendMessage (IncMasterN 1))    -- shift windows: more in master
+    , ("M-S-<Left>",  sendMessage (IncMasterN 1))    -- shift windows: more in master
+    , ("M-S-<Right>", sendMessage (IncMasterN (-1))) -- shift windows: fewer in master
 
     -- master window operations
     , ("M-<Delete>", windows W.focusMaster)