diff --git a/.github/workflows/quality.yaml b/.github/workflows/quality.yaml
new file mode 100644
index 0000000..dcf74d2
--- /dev/null
+++ b/.github/workflows/quality.yaml
@@ -0,0 +1,88 @@
+name: Code Quality
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      lua: ${{ steps.changes.outputs.lua }}
+      markdown: ${{ steps.changes.outputs.markdown }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: changes
+        with:
+          filters: |
+            lua:
+              - 'lua/**'
+              - 'colors/**'
+              - '*.lua'
+              - '.luarc.json'
+              - '*.toml'
+            markdown:
+              - '*.md'
+
+  lua-format:
+    name: Lua Format Check
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.lua == 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: JohnnyMorganz/stylua-action@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          version: 2.1.0
+          args: --check .
+
+  lua-lint:
+    name: Lua Lint Check
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.lua == 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Lint with Selene
+        uses: NTBBloodbath/selene-action@v1.0.0
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --display-style quiet .
+
+  lua-typecheck:
+    name: Lua Type Check
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.lua == 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Run Lua LS Type Check
+        uses: mrcjkb/lua-typecheck-action@v0
+        with:
+          checklevel: Warning
+          directories: lua
+          configpath: .luarc.json
+
+  markdown-format:
+    name: Markdown Format Check
+    runs-on: ubuntu-latest
+    needs: changes
+    if: ${{ needs.changes.outputs.markdown == 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 8
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+      - name: Install prettier
+        run: pnpm add -g prettier@3.1.0
+      - name: Check markdown formatting with prettier
+        run: prettier --check .
diff --git a/.luarc.json b/.luarc.json
new file mode 100644
index 0000000..3ccfeda
--- /dev/null
+++ b/.luarc.json
@@ -0,0 +1,8 @@
+{
+  "runtime.version": "Lua 5.1",
+  "runtime.path": ["lua/?.lua", "lua/?/init.lua"],
+  "diagnostics.globals": ["vim"],
+  "workspace.library": ["$VIMRUNTIME/lua", "${3rd}/luv/library"],
+  "workspace.checkThirdParty": false,
+  "completion.callSnippet": "Replace"
+}
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..3477598
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,17 @@
+minimum_pre_commit_version: '3.5.0'
+
+repos:
+  - repo: https://github.com/JohnnyMorganz/StyLua
+    rev: v2.3.1
+    hooks:
+      - id: stylua-github
+        name: stylua (Lua formatter)
+        files: \.lua$
+        pass_filenames: true
+
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: v4.0.0-alpha.8
+    hooks:
+      - id: prettier
+        name: prettier (format markdown)
+        files: \.md$
diff --git a/lua/midnight/init.lua b/lua/midnight/init.lua
index 06b43aa..7d03715 100644
--- a/lua/midnight/init.lua
+++ b/lua/midnight/init.lua
@@ -1,10 +1,15 @@
 local M = {}
 
----@param opts? table
+---@class MidnightConfig
+---@field [string] any
+
+---@param opts? MidnightConfig
+---@return nil
 function M.setup(opts)
   opts = opts or {}
 end
 
+---@return nil
 function M.load()
   if vim.g.colors_name then
     vim.cmd('hi clear')