diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..6eae6a8
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,94 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  # Job 1: Build & Type Check
+  build:
+    name: Build & Type Check
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Type check & Build
+        run: npm run build
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/
+          retention-days: 7
+
+  # Job 2: Lint
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run ESLint
+        run: npm run lint
+
+  # Job 3: Bundle Size Check
+  bundle-size:
+    name: Bundle Size Check
+    runs-on: ubuntu-latest
+    needs: build
+    timeout-minutes: 10
+
+    steps:
+      - name: Download build artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+      - name: Check bundle size
+        env:
+          BUNDLE_SIZE_THRESHOLD: 500
+        run: |
+          BUNDLE_SIZE_BYTES=$(find dist -type f -printf '%s\n' | awk '{sum += $1} END {print sum + 0}')
+          BUNDLE_SIZE_KB=$(( (BUNDLE_SIZE_BYTES + 1023) / 1024 ))
+          THRESHOLD_BYTES=$(( BUNDLE_SIZE_THRESHOLD * 1024 ))
+          echo "Bundle size: ${BUNDLE_SIZE_KB}KB (${BUNDLE_SIZE_BYTES} bytes)"
+          if [ "$BUNDLE_SIZE_BYTES" -gt "$THRESHOLD_BYTES" ]; then
+            echo "::warning::Bundle size ${BUNDLE_SIZE_KB}KB exceeds ${BUNDLE_SIZE_THRESHOLD}KB threshold."
+          else
+            echo "✅ Bundle size ${BUNDLE_SIZE_KB}KB is within threshold"
+          fi