diff --git a/.github/workflows/firebase-hosting-merge.yml b/.github/workflows/firebase-hosting-merge.yml
index 02a81d7..f94951b 100644
--- a/.github/workflows/firebase-hosting-merge.yml
+++ b/.github/workflows/firebase-hosting-merge.yml
@@ -13,7 +13,9 @@ permissions:
 
 jobs:
   build_and_deploy:
+    if: ${{ github.ref == 'refs/heads/master' }}
     runs-on: ubuntu-latest
+    environment: production
     env:
       APP_TITLE: ${{ vars.APP_TITLE || secrets.APP_TITLE }}
       APP_API_URL: ${{ vars.APP_API_URL || vars.API_URL || secrets.APP_API_URL || secrets.API_URL }}
@@ -40,6 +42,37 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Validate required environment variables
+        run: |
+          missing=()
+          required=(
+            APP_TITLE
+            APP_API_URL
+            OPENAI_API_KEY
+            OPEN_WEATHER_MAP_API_KEY
+            FIREBASE_API_KEY
+            FIREBASE_AUTH_DOMAIN
+            FIREBASE_DATABASE_URL
+            FIREBASE_PROJECT_ID
+            FIREBASE_STORAGE_BUCKET
+            FIREBASE_MESSAGING_SENDER_ID
+            FIREBASE_APP_ID
+            FIREBASE_MEASUREMENT_ID
+          )
+
+          for name in "${required[@]}"; do
+            if [ -z "${!name}" ]; then
+              missing+=("$name")
+            fi
+          done
+
+          if [ "${#missing[@]}" -gt 0 ]; then
+            echo "Missing required workflow environment variables:"
+            printf -- '- %s\n' "${missing[@]}"
+            echo "Check GitHub repository/environment Variables and Secrets configuration."
+            exit 1
+          fi
+
       - name: Generate Angular environment files
         run: npm run generate:env
 
diff --git a/.github/workflows/firebase-hosting-pull-request.yml b/.github/workflows/firebase-hosting-pull-request.yml
index f8f2226..595e1ad 100644
--- a/.github/workflows/firebase-hosting-pull-request.yml
+++ b/.github/workflows/firebase-hosting-pull-request.yml
@@ -2,7 +2,10 @@
 # https://github.com/firebase/firebase-tools
 
 name: Deploy to Firebase Hosting on PR
-on: pull_request
+on:
+  pull_request:
+    branches:
+      - dev
 permissions:
   checks: write
   contents: read
@@ -11,28 +14,9 @@ jobs:
   build_and_preview:
     if: ${{ github.event.pull_request.head.repo.full_name == github.repository }}
     runs-on: ubuntu-latest
-    env:
-      APP_TITLE: ${{ vars.APP_TITLE || secrets.APP_TITLE }}
-      APP_API_URL: ${{ vars.APP_API_URL || vars.API_URL || secrets.APP_API_URL || secrets.API_URL }}
-      OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY || vars.OPENAI_API_KEY }}
-      OPEN_WEATHER_MAP_API_KEY: ${{ secrets.OPEN_WEATHER_MAP_API_KEY || vars.OPEN_WEATHER_MAP_API_KEY }}
-      FIREBASE_API_KEY: ${{ vars.FIREBASE_API_KEY || secrets.FIREBASE_API_KEY }}
-      FIREBASE_AUTH_DOMAIN: ${{ vars.FIREBASE_AUTH_DOMAIN || secrets.FIREBASE_AUTH_DOMAIN }}
-      FIREBASE_DATABASE_URL: ${{ vars.FIREBASE_DATABASE_URL || secrets.FIREBASE_DATABASE_URL }}
-      FIREBASE_PROJECT_ID: ${{ vars.FIREBASE_PROJECT_ID || secrets.FIREBASE_PROJECT_ID }}
-      FIREBASE_STORAGE_BUCKET: ${{ vars.FIREBASE_STORAGE_BUCKET || secrets.FIREBASE_STORAGE_BUCKET }}
-      FIREBASE_MESSAGING_SENDER_ID: ${{ vars.FIREBASE_MESSAGING_SENDER_ID || secrets.FIREBASE_MESSAGING_SENDER_ID }}
-      FIREBASE_APP_ID: ${{ vars.FIREBASE_APP_ID || secrets.FIREBASE_APP_ID }}
-      FIREBASE_MEASUREMENT_ID: ${{ vars.FIREBASE_MEASUREMENT_ID || secrets.FIREBASE_MEASUREMENT_ID }}
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version: 20
-          cache: npm
       - run: npm ci
-      - run: npm run generate:env
-      - run: npm run build
       - uses: FirebaseExtended/action-hosting-deploy@v0
         with:
           repoToken: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/firebase_deployment_workflow.yml b/.github/workflows/firebase_deployment_workflow.yml
index 7342f58..fbdcb31 100644
--- a/.github/workflows/firebase_deployment_workflow.yml
+++ b/.github/workflows/firebase_deployment_workflow.yml
@@ -9,6 +9,7 @@ permissions:
 jobs:
   deploy:
     runs-on: ubuntu-latest
+    environment: production
     env:
       APP_TITLE: ${{ vars.APP_TITLE || secrets.APP_TITLE }}
       APP_API_URL: ${{ vars.APP_API_URL || vars.API_URL || secrets.APP_API_URL || secrets.API_URL }}
@@ -35,6 +36,37 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
+      - name: Validate required environment variables
+        run: |
+          missing=()
+          required=(
+            APP_TITLE
+            APP_API_URL
+            OPENAI_API_KEY
+            OPEN_WEATHER_MAP_API_KEY
+            FIREBASE_API_KEY
+            FIREBASE_AUTH_DOMAIN
+            FIREBASE_DATABASE_URL
+            FIREBASE_PROJECT_ID
+            FIREBASE_STORAGE_BUCKET
+            FIREBASE_MESSAGING_SENDER_ID
+            FIREBASE_APP_ID
+            FIREBASE_MEASUREMENT_ID
+          )
+
+          for name in "${required[@]}"; do
+            if [ -z "${!name}" ]; then
+              missing+=("$name")
+            fi
+          done
+
+          if [ "${#missing[@]}" -gt 0 ]; then
+            echo "Missing required workflow environment variables:"
+            printf -- '- %s\n' "${missing[@]}"
+            echo "Check GitHub repository/environment Variables and Secrets configuration."
+            exit 1
+          fi
+
       - name: Generate Angular environment files
         run: npm run generate:env