feat: enhance database reliability, add rate limiting, and improve email compatibility

database.py

@@ -1,64 +1,213 @@
 import os
 import psycopg2
-from psycopg2 import pool, IntegrityError
+from psycopg2 import pool, IntegrityError, OperationalError
 from dotenv import load_dotenv
 import logging
+import threading
+import time
+from contextlib import contextmanager
 
 load_dotenv()
 
 # Global connection pool
 _connection_pool = None
+_pool_lock = threading.Lock()
+_pool_stats = {
+    'connections_created': 0,
+    'connections_failed': 0,
+    'pool_recreated': 0
+}
+
+logger = logging.getLogger(__name__)
+
+class SimpleRobustPool:
+    """Simplified robust connection pool"""
+    
+    def __init__(self, minconn=3, maxconn=15, **kwargs):
+        self.minconn = minconn
+        self.maxconn = maxconn
+        self.kwargs = kwargs
+        self.pool = None
+        self._create_pool()
+    
+    def _create_pool(self):
+        """Create or recreate the connection pool"""
+        try:
+            if self.pool:
+                try:
+                    self.pool.closeall()
+                except:
+                    pass
+            
+            self.pool = psycopg2.pool.ThreadedConnectionPool(
+                minconn=self.minconn,
+                maxconn=self.maxconn,
+                **self.kwargs
+            )
+            _pool_stats['pool_recreated'] += 1
+            logger.info(f"Connection pool created: {self.minconn}-{self.maxconn} connections")
+            
+        except Exception as e:
+            logger.error(f"Failed to create connection pool: {e}")
+            raise
+    
+    def _test_connection(self, conn):
+        """Simple connection test without transaction conflicts"""
+        try:
+            if conn.closed:
+                return False
+            
+            # Simple test that doesn't interfere with transactions
+            conn.poll()
+            return conn.status == psycopg2.extensions.STATUS_READY or conn.status == psycopg2.extensions.STATUS_BEGIN
+            
+        except Exception:
+            return False
+    
+    def getconn(self, retry_count=2):
+        """Get a connection with simplified retry logic"""
+        for attempt in range(retry_count):
+            try:
+                conn = self.pool.getconn()
+                
+                # Simple connection test
+                if not self._test_connection(conn):
+                    logger.warning("Got bad connection, discarding and retrying")
+                    try:
+                        self.pool.putconn(conn, close=True)
+                    except:
+                        pass
+                    continue
+                
+                _pool_stats['connections_created'] += 1
+                return conn
+                
+            except Exception as e:
+                logger.error(f"Error getting connection (attempt {attempt + 1}): {e}")
+                _pool_stats['connections_failed'] += 1
+                
+                if attempt == retry_count - 1:
+                    # Last attempt failed, try to recreate pool
+                    logger.warning("Recreating connection pool due to failures")
+                    try:
+                        self._create_pool()
+                        conn = self.pool.getconn()
+                        if self._test_connection(conn):
+                            return conn
+                    except Exception as recreate_error:
+                        logger.error(f"Failed to recreate pool: {recreate_error}")
+                        raise
+                
+                # Wait before retry
+                time.sleep(0.5)
+        
+        raise Exception("Failed to get connection after retries")
+    
+    def putconn(self, conn, close=False):
+        """Return connection to pool"""
+        try:
+            # Check if connection should be closed
+            if conn.closed or close:
+                close = True
+            
+            self.pool.putconn(conn, close=close)
+            
+        except Exception as e:
+            logger.error(f"Error returning connection to pool: {e}")
+            try:
+                conn.close()
+            except:
+                pass
+    
+    def closeall(self):
+        """Close all connections"""
+        if self.pool:
+            self.pool.closeall()
 
 def get_connection_pool():
     """Initialize and return the connection pool"""
     global _connection_pool
+    with _pool_lock:
         if _connection_pool is None:
             try:
-            _connection_pool = psycopg2.pool.ThreadedConnectionPool(
+                _connection_pool = SimpleRobustPool(
-                minconn=2,
+                    minconn=int(os.getenv('DB_POOL_MIN', 3)),
-                maxconn=20,
+                    maxconn=int(os.getenv('DB_POOL_MAX', 15)),
                     host=os.getenv("PG_HOST"),
-                port=os.getenv("PG_PORT", 5432),
+                    port=int(os.getenv("PG_PORT", 5432)),
-                dbname=os.getenv("PG_DATABASE"),
+                    database=os.getenv("PG_DATABASE"),
                     user=os.getenv("PG_USER"),
                     password=os.getenv("PG_PASSWORD"),
-                connect_timeout=5
+                    connect_timeout=int(os.getenv('DB_CONNECT_TIMEOUT', 10)),
+                    application_name="rideaware_newsletter"
                 )
-            logging.info("Database connection pool created successfully")
+                logger.info("Database connection pool initialized successfully")
+                
             except Exception as e:
-            logging.error(f"Error creating connection pool: {e}")
+                logger.error(f"Error creating connection pool: {e}")
                 raise
+        
         return _connection_pool
 
-def get_connection():
+@contextmanager
-    """Get a connection from the pool"""
+def get_db_connection():
+    """Context manager for database connections"""
+    conn = None
     try:
         pool = get_connection_pool()
         conn = pool.getconn()
-        if conn.closed:
+        yield conn
-            # Connection is closed, remove it and get a new one
+        
-            pool.putconn(conn, close=True)
-            conn = pool.getconn()
-        return conn
     except Exception as e:
-        logging.error(f"Error getting connection from pool: {e}")
+        logger.error(f"Database connection error: {e}")
+        if conn:
+            try:
+                conn.rollback()
+            except:
+                pass
         raise
         
-def return_connection(conn):
+    finally:
-    """Return a connection to the pool"""
+        if conn:
             try:
                 pool = get_connection_pool()
                 pool.putconn(conn)
             except Exception as e:
-        logging.error(f"Error returning connection to pool: {e}")
+                logger.error(f"Error returning connection: {e}")
+
+def get_connection():
+    """Get a connection from the pool (legacy interface)"""
+    try:
+        pool = get_connection_pool()
+        return pool.getconn()
+    except Exception as e:
+        logger.error(f"Error getting connection from pool: {e}")
+        raise
+
+def return_connection(conn):
+    """Return a connection to the pool (legacy interface)"""
+    try:
+        pool = get_connection_pool()
+        pool.putconn(conn)
+    except Exception as e:
+        logger.error(f"Error returning connection to pool: {e}")
 
 def close_all_connections():
     """Close all connections in the pool"""
     global _connection_pool
+    with _pool_lock:
         if _connection_pool:
+            try:
                 _connection_pool.closeall()
+                logger.info("All database connections closed")
+            except Exception as e:
+                logger.error(f"Error closing connections: {e}")
+            finally:
                 _connection_pool = None
-        logging.info("All database connections closed")
+
+def get_pool_stats():
+    """Get connection pool statistics"""
+    return _pool_stats.copy()
 
 def column_exists(cursor, table_name, column_name):
     """Check if a column exists in a table"""
@@ -84,11 +233,9 @@ def index_exists(cursor, index_name):
 
 def init_db():
     """Initialize database tables and indexes"""
-    conn = None
+    with get_db_connection() as conn:
         try:
-        conn = get_connection()
+            with conn.cursor() as cursor:
-        cursor = conn.cursor()
-        
                 # Create subscribers table
                 cursor.execute("""
                     CREATE TABLE IF NOT EXISTS subscribers (
@@ -103,7 +250,7 @@ def init_db():
                         ALTER TABLE subscribers 
                         ADD COLUMN created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
                     """)
-            logging.info("Added created_at column to subscribers table")
+                    logger.info("Added created_at column to subscribers table")
                 
                 # Create newsletters table
                 cursor.execute("""
@@ -116,107 +263,79 @@ def init_db():
                 """)
                 
                 # Create indexes only if they don't exist
-        if not index_exists(cursor, 'idx_newsletters_sent_at'):
+                indexes = [
-            cursor.execute("CREATE INDEX idx_newsletters_sent_at ON newsletters(sent_at DESC)")
+                    ("idx_newsletters_sent_at", "CREATE INDEX IF NOT EXISTS idx_newsletters_sent_at ON newsletters(sent_at DESC)"),
-            logging.info("Created index idx_newsletters_sent_at")
+                    ("idx_subscribers_email", "CREATE INDEX IF NOT EXISTS idx_subscribers_email ON subscribers(email)"),
+                    ("idx_subscribers_created_at", "CREATE INDEX IF NOT EXISTS idx_subscribers_created_at ON subscribers(created_at DESC)")
+                ]
                 
-        if not index_exists(cursor, 'idx_subscribers_email'):
+                for index_name, create_sql in indexes:
-            cursor.execute("CREATE INDEX idx_subscribers_email ON subscribers(email)")
+                    cursor.execute(create_sql)
-            logging.info("Created index idx_subscribers_email")
+                    logger.info(f"Ensured index {index_name} exists")
-        
-        if not index_exists(cursor, 'idx_subscribers_created_at'):
-            cursor.execute("CREATE INDEX idx_subscribers_created_at ON subscribers(created_at DESC)")
-            logging.info("Created index idx_subscribers_created_at")
                 
                 conn.commit()
-        cursor.close()
+                logger.info("Database tables and indexes initialized successfully")
-        logging.info("Database tables and indexes initialized successfully")
                 
         except Exception as e:
-        logging.error(f"Error initializing database: {e}")
+            logger.error(f"Error initializing database: {e}")
-        if conn:
             conn.rollback()
             raise
-    finally:
-        if conn:
-            return_connection(conn)
 
 def add_email(email):
-    """Add email to subscribers with connection pooling"""
+    """Add email to subscribers with robust connection handling"""
-    conn = None
+    with get_db_connection() as conn:
         try:
-        conn = get_connection()
+            with conn.cursor() as cursor:
-        cursor = conn.cursor()
                 cursor.execute("INSERT INTO subscribers (email) VALUES (%s)", (email,))
                 conn.commit()
-        cursor.close()
+                logger.info(f"Email added successfully: {email}")
-        logging.info(f"Email added successfully: {email}")
                 return True
                 
         except IntegrityError:
             # Email already exists
-        if conn:
             conn.rollback()
-        logging.info(f"Email already exists: {email}")
+            logger.info(f"Email already exists: {email}")
             return False
             
         except Exception as e:
-        if conn:
             conn.rollback()
-        logging.error(f"Error adding email {email}: {e}")
+            logger.error(f"Error adding email {email}: {e}")
             return False
 
-    finally:
-        if conn:
-            return_connection(conn)
-
 def remove_email(email):
-    """Remove email from subscribers with connection pooling"""
+    """Remove email from subscribers with robust connection handling"""
-    conn = None
+    with get_db_connection() as conn:
         try:
-        conn = get_connection()
+            with conn.cursor() as cursor:
-        cursor = conn.cursor()
                 cursor.execute("DELETE FROM subscribers WHERE email = %s", (email,))
                 conn.commit()
                 rows_affected = cursor.rowcount
-        cursor.close()
                 
                 if rows_affected > 0:
-            logging.info(f"Email removed successfully: {email}")
+                    logger.info(f"Email removed successfully: {email}")
                     return True
                 else:
-            logging.info(f"Email not found for removal: {email}")
+                    logger.info(f"Email not found for removal: {email}")
                     return False
                     
         except Exception as e:
-        if conn:
             conn.rollback()
-        logging.error(f"Error removing email {email}: {e}")
+            logger.error(f"Error removing email {email}: {e}")
             return False
 
-    finally:
-        if conn:
-            return_connection(conn)
-
 def get_subscriber_count():
     """Get total number of subscribers"""
-    conn = None
+    with get_db_connection() as conn:
         try:
-        conn = get_connection()
+            with conn.cursor() as cursor:
-        cursor = conn.cursor()
                 cursor.execute("SELECT COUNT(*) FROM subscribers")
                 count = cursor.fetchone()[0]
-        cursor.close()
                 return count
                 
         except Exception as e:
-        logging.error(f"Error getting subscriber count: {e}")
+            logger.error(f"Error getting subscriber count: {e}")
             return 0
 
-    finally:
-        if conn:
-            return_connection(conn)
-
 # Cleanup function for graceful shutdown
 import atexit
 atexit.register(close_all_connections)

requirements.txt

@@ -1,4 +1,5 @@
 gunicorn
-flask
 python-dotenv
 psycopg2-binary
+Flask
+Flask-Limiter

server.py

@@ -5,6 +5,8 @@ from threading import Thread
 import smtplib
 from email.mime.text import MIMEText
 from flask import Flask, render_template, request, jsonify, g
+from flask_limiter import Limiter
+from flask_limiter.util import get_remote_address
 from dotenv import load_dotenv
 from database import init_db, get_connection, return_connection, add_email, remove_email
 
@@ -17,8 +19,19 @@ SMTP_PASSWORD = os.getenv('SMTP_PASSWORD')
 
 app = Flask(__name__)
 
+# Rate limiting setup
+limiter = Limiter(
+    key_func=get_remote_address,
+    app=app,
+    default_limits=["1000 per hour", "100 per minute"],
+    storage_uri="memory://"
+)
+
 # Configure logging
-logging.basicConfig(level=logging.INFO)
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s %(levelname)s [%(name)s] %(message)s'
+)
 
 # Cache configuration
 _newsletter_cache = {}
@@ -132,24 +145,20 @@ def after_request(response):
     
     return response
 
-def send_confirmation_email(to_address: str, unsubscribe_link: str):
+def send_confirmation_email(to_address: str, html_body: str):
     """
     Sends the HTML confirmation email to `to_address`.
-    This runs inside its own SMTP_SSL connection with reduced timeout.
+    html_body is pre-rendered to avoid Flask context issues.
     """
     try:
         subject = "Thanks for subscribing!"
-        html_body = render_template(
-            "confirmation_email.html",
-            unsubscribe_link=unsubscribe_link
-        )
 
         msg = MIMEText(html_body, "html", "utf-8")
         msg["Subject"] = subject
         msg["From"] = SMTP_USER
         msg["To"] = to_address
 
-        with smtplib.SMTP_SSL(SMTP_SERVER, SMTP_PORT, timeout=5) as server:
+        with smtplib.SMTP_SSL(SMTP_SERVER, SMTP_PORT, timeout=10) as server:
             server.login(SMTP_USER, SMTP_PASSWORD)
             server.sendmail(SMTP_USER, [to_address], msg.as_string())
             
@@ -158,11 +167,11 @@ def send_confirmation_email(to_address: str, unsubscribe_link: str):
     except Exception as e:
         app.logger.error(f"Failed to send email to {to_address}: {e}")
 
-def send_confirmation_async(email, unsubscribe_link):
+def send_confirmation_async(email, html_body):
     """
     Wrapper for threading.Thread target.
     """
-    send_confirmation_email(email, unsubscribe_link)
+    send_confirmation_email(email, html_body)
 
 @app.route("/", methods=["GET"])
 def index():
@@ -170,6 +179,7 @@ def index():
     return render_template("index.html")
 
 @app.route("/subscribe", methods=["POST"])
+@limiter.limit("5 per minute")  # Strict rate limit for subscriptions
 def subscribe():
     """Subscribe endpoint with optimized database handling"""
     data = request.get_json() or {}
@@ -184,12 +194,17 @@ def subscribe():
     
     try:
         if add_email(email):
+            # Render the template in the main thread (with Flask context)
             unsubscribe_link = f"{request.url_root}unsubscribe?email={email}"
+            html_body = render_template(
+                "confirmation_email.html",
+                unsubscribe_link=unsubscribe_link
+            )
 
-            # Start email sending in background thread
+            # Start email sending in background thread with pre-rendered HTML
             Thread(
                 target=send_confirmation_async,
-                args=(email, unsubscribe_link),
+                args=(email, html_body),
                 daemon=True
             ).start()
 
@@ -202,6 +217,7 @@ def subscribe():
         return jsonify(error="Internal server error"), 500
 
 @app.route("/unsubscribe", methods=["GET"])
+@limiter.limit("10 per minute")
 def unsubscribe():
     """Unsubscribe endpoint with optimized database handling"""
     email = request.args.get("email")
@@ -220,6 +236,7 @@ def unsubscribe():
         return "Internal server error", 500
 
 @app.route("/newsletters", methods=["GET"])
+@limiter.limit("30 per minute")
 def newsletters():
     """
     List all newsletters (newest first) with caching for better performance.
@@ -232,6 +249,7 @@ def newsletters():
         return "Internal server error", 500
 
 @app.route("/newsletter/<int:newsletter_id>", methods=["GET"])
+@limiter.limit("60 per minute")
 def newsletter_detail(newsletter_id):
     """
     Show a single newsletter by its ID with caching.
@@ -248,6 +266,7 @@ def newsletter_detail(newsletter_id):
         return "Internal server error", 500
 
 @app.route("/admin/clear-cache", methods=["POST"])
+@limiter.limit("5 per minute")
 def clear_cache():
     """Admin endpoint to clear newsletter cache"""
     try:
@@ -258,10 +277,16 @@ def clear_cache():
         return jsonify(error="Failed to clear cache"), 500
 
 @app.route("/health", methods=["GET"])
+@limiter.limit("120 per minute")
 def health_check():
     """Health check endpoint for monitoring"""
     return jsonify(status="healthy", timestamp=time.time()), 200
 
+# Rate limit error handler
+@app.errorhandler(429)
+def ratelimit_handler(e):
+    return jsonify(error="Rate limit exceeded. Please try again later."), 429
+
 # Error handlers
 @app.errorhandler(404)
 def not_found(error):

templates/confirmation_email.html

@@ -13,6 +13,7 @@
         </xml>
     </noscript>
     <![endif]-->
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
     <style>
         /* Reset and base styles */
         * {
@@ -22,12 +23,12 @@
         }
 
         body {
+            margin: 0;
+            padding: 0;
             font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
             line-height: 1.6;
             color: #1a1a1a;
             background-color: #f8fafc;
-            margin: 0;
-            padding: 0;
             -webkit-text-size-adjust: 100%;
             -ms-text-size-adjust: 100%;
         }
@@ -40,71 +41,41 @@
 
         img {
             border: 0;
+            max-width: 100%;
             height: auto;
             line-height: 100%;
             outline: none;
             text-decoration: none;
-            -ms-interpolation-mode: bicubic;
-            max-width: 100%;
         }
 
-        /* Container */
+        /* Email container */
-        .email-container {
+        .email-wrapper {
             max-width: 600px;
             margin: 0 auto;
             background-color: #ffffff;
-            border-radius: 16px;
-            box-shadow: 0 10px 30px rgba(30, 78, 156, 0.1);
-            overflow: hidden;
         }
 
-        .email-wrapper {
+        /* Header styles */
-            background-color: #f8fafc;
-            padding: 20px;
-        }
-
-        /* Header */
         .header {
-            background: linear-gradient(135deg, #1e4e9c 0%, #337cf2 50%, #00d4ff 100%);
+            background: linear-gradient(135deg, #1e4e9c 0%, #337cf2 100%);
+            background-color: #1e4e9c; /* Fallback */
             padding: 50px 30px;
             text-align: center;
-            position: relative;
+            color: white;
-        }
-
-        .header::before {
-            content: '';
-            position: absolute;
-            top: 0;
-            left: 0;
-            right: 0;
-            bottom: 0;
-            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="celebration" width="50" height="50" patternUnits="userSpaceOnUse"><circle cx="10" cy="10" r="2" fill="rgba(255,255,255,0.1)"/><circle cx="40" cy="25" r="1.5" fill="rgba(0,212,255,0.2)"/><circle cx="25" cy="40" r="1" fill="rgba(255,255,255,0.15)"/></pattern></defs><rect width="100%" height="100%" fill="url(%23celebration)"/></svg>');
-            opacity: 0.4;
         }
 
         .welcome-icon {
-            width: 80px;
+            font-size: 3rem;
-            height: 80px;
+            margin-bottom: 20px;
-            background: rgba(255, 255, 255, 0.2);
+            display: block;
-            border-radius: 50%;
-            display: flex;
-            align-items: center;
-            justify-content: center;
-            margin: 0 auto 20px;
-            font-size: 2.5rem;
-            position: relative;
-            z-index: 1;
         }
 
         .logo {
             font-size: 24px;
             font-weight: 700;
             color: white;
-            text-decoration: none;
-            position: relative;
-            z-index: 1;
             margin-bottom: 15px;
-            display: inline-block;
+            display: block;
         }
 
         .logo-accent {
@@ -116,19 +87,16 @@
             font-size: 28px;
             font-weight: 800;
             margin: 0 0 10px;
-            position: relative;
-            z-index: 1;
         }
 
-        .header .subtitle {
+        .subtitle {
             color: rgba(255, 255, 255, 0.9);
             font-size: 16px;
             font-weight: 300;
-            position: relative;
+            margin: 0;
-            z-index: 1;
         }
 
-        /* Content */
+        /* Content styles */
         .content {
             padding: 40px 30px;
             text-align: center;
@@ -151,6 +119,7 @@
         /* Feature highlights */
         .features {
             background: linear-gradient(135deg, rgba(30, 78, 156, 0.05) 0%, rgba(0, 212, 255, 0.05) 100%);
+            background-color: #f8fafc; /* Fallback */
             border-radius: 12px;
             padding: 30px 25px;
             margin: 30px 0;
@@ -165,10 +134,7 @@
         }
 
         .feature-grid {
-            display: grid;
+            width: 100%;
-            grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
-            gap: 20px;
-            margin-top: 20px;
         }
 
         .feature-item {
@@ -176,6 +142,7 @@
             padding: 15px;
             background: white;
             border-radius: 10px;
+            margin-bottom: 15px;
             box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
         }
 
@@ -198,7 +165,7 @@
             line-height: 1.4;
         }
 
-        /* CTA Button */
+        /* CTA styles */
         .cta-section {
             margin: 35px 0;
             padding: 25px;
@@ -207,24 +174,22 @@
         .cta-button {
             display: inline-block;
             background: linear-gradient(135deg, #1e4e9c 0%, #337cf2 100%);
-            color: white;
+            background-color: #1e4e9c; /* Fallback */
+            color: white !important;
             text-decoration: none;
             padding: 15px 35px;
             border-radius: 25px;
             font-weight: 600;
             font-size: 16px;
-            transition: all 0.3s ease;
             box-shadow: 0 5px 15px rgba(30, 78, 156, 0.3);
         }
 
         .cta-button:hover {
-            transform: translateY(-2px);
+            background-color: #337cf2;
-            box-shadow: 0 8px 25px rgba(30, 78, 156, 0.4);
             text-decoration: none;
-            color: white;
         }
 
-        /* Social links */
+        /* Social section */
         .social-section {
             margin: 30px 0;
             padding: 25px;
@@ -240,9 +205,7 @@
         }
 
         .social-links {
-            display: flex;
+            text-align: center;
-            justify-content: center;
-            gap: 15px;
         }
 
         .social-link {
@@ -250,22 +213,21 @@
             width: 40px;
             height: 40px;
             background: linear-gradient(135deg, #1e4e9c 0%, #337cf2 100%);
+            background-color: #1e4e9c; /* Fallback */
             color: white;
             text-decoration: none;
             border-radius: 50%;
-            display: flex;
+            line-height: 40px;
-            align-items: center;
-            justify-content: center;
             font-size: 16px;
-            transition: all 0.3s ease;
+            margin: 0 7px;
+            text-align: center;
         }
 
         .social-link:hover {
-            transform: translateY(-2px) scale(1.05);
+            background-color: #337cf2;
-            box-shadow: 0 5px 15px rgba(30, 78, 156, 0.3);
         }
 
-        /* Footer */
+        /* Footer styles */
         .footer {
             background: #1a1a1a;
             color: white;
@@ -277,9 +239,8 @@
             margin-bottom: 20px;
         }
 
-        .footer p {
+        .footer-content p {
             margin: 5px 0;
-            opacity: 0.8;
             font-size: 14px;
         }
 
@@ -300,58 +261,43 @@
             text-decoration: underline;
         }
 
-        /* Links */
-        a {
-            color: #337cf2;
-            text-decoration: none;
-            font-weight: 500;
-        }
-
-        a:hover {
-            color: #1e4e9c;
-            text-decoration: underline;
-        }
-
         /* Mobile responsive */
         @media only screen and (max-width: 600px) {
             .email-wrapper {
-                padding: 10px;
+                width: 100% !important;
             }
             
             .header {
-                padding: 40px 20px;
+                padding: 40px 20px !important;
             }
             
             .header h1 {
-                font-size: 24px;
+                font-size: 24px !important;
             }
             
             .content {
-                padding: 30px 20px;
+                padding: 30px 20px !important;
             }
             
             .features {
-                padding: 25px 20px;
+                padding: 25px 20px !important;
             }
             
-            .feature-grid {
+            .feature-item {
-                grid-template-columns: 1fr;
+                margin-bottom: 10px !important;
-                gap: 15px;
             }
             
-            .social-links {
+            .social-link {
-                gap: 10px;
+                margin: 0 5px !important;
-            }
-            
-            .footer {
-                padding: 25px 20px;
             }
         }
     </style>
 </head>
 <body>
+    <table role="presentation" cellspacing="0" cellpadding="0" border="0" width="100%" style="background-color: #f8fafc;">
+        <tr>
+            <td align="center">
                 <div class="email-wrapper">
-        <div class="email-container">
                     <!-- Header -->
                     <div class="header">
                         <div class="welcome-icon">🎉</div>
@@ -368,7 +314,7 @@
                             We're absolutely thrilled to have you join our community of passionate cyclists. Get ready for exclusive insights, training tips, feature updates, and much more delivered straight to your inbox.
                         </p>
 
-                <!-- What to expect -->
+                        <!-- Features -->
                         <div class="features">
                             <h3>What to expect from us:</h3>
                             <div class="feature-grid">
@@ -428,7 +374,7 @@
                         <div class="unsubscribe">
                             <p>
                                 <a href="{{ unsubscribe_link }}">Unsubscribe</a> | 
-                        <a href="mailto:support@rideaware.com">Contact Support</a> |
+                                <a href="mailto:support@rideaware.com">Contact Support</a>
                             </p>
                             <p style="font-size: 12px; color: #6b7280; margin-top: 10px;">
                                 © 2025 RideAware. All rights reserved.
@@ -439,6 +385,8 @@
                         </div>
                     </div>
                 </div>
-    </div>
+            </td>
+        </tr>
+    </table>
 </body>
 </html>