diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..64ebdaa
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,6 @@
+RESEND_API_KEY=
+RESEND_FROM_EMAIL=
+RESEND_TO_EMAIL=
+NEXT_PUBLIC_RECAPTCHA_SITE_KEY=
+RECAPTCHA_SECRET_KEY=
+NEXT_PUBLIC_BASE_URL=
diff --git a/.gitignore b/.gitignore
index 4bb68e0..5355dde 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,6 +32,7 @@ yarn-error.log*
 
 # env files (can opt-in for committing if needed)
 .env*
+!.env.example
 
 # vercel
 .vercel
diff --git a/app/blog/[slug]/page.tsx b/app/blog/[slug]/page.tsx
index d811660..5a11f3a 100644
--- a/app/blog/[slug]/page.tsx
+++ b/app/blog/[slug]/page.tsx
@@ -3,6 +3,7 @@ import Image from 'next/image';
 import Link from 'next/link';
 import { notFound } from 'next/navigation';
 import { getPosts, getPostBySlug, getRelatedPosts } from '@/content/posts';
+import { JsonLd } from '@/components/ui/JsonLd';
 import { CtaBanner } from '@/components/sections/CtaBanner';
 import { Calendar, User, ArrowLeft, ArrowRight } from 'lucide-react';
 import { companyDetails } from '@/content/company';
@@ -139,14 +140,8 @@ export default async function BlogPostPage({ params }: BlogPostPageProps) {
   return (
     <main className="bg-slate-50 pt-24 pb-16">
       {/* Skrypty JSON-LD dla SEO */}
-      <script
-        type="application/ld+json"
-        dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLdArticle) }}
-      />
-      <script
-        type="application/ld+json"
-        dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLdBreadcrumb) }}
-      />
+      <JsonLd data={jsonLdArticle} />
+      <JsonLd data={jsonLdBreadcrumb} />
 
       <article className="max-w-4xl mx-auto px-4 sm:px-6 lg:px-8">
         {/* Powrót */}
@@ -203,6 +198,8 @@ export default async function BlogPostPage({ params }: BlogPostPageProps) {
           prose-img:rounded-xl prose-img:shadow-md
           marker:text-accent"
         >
+          {/* Dane blogowe są obecnie lokalnym, zaufanym contentem; nie dodajemy ciężkiej biblioteki DOMPurify bez potrzeby. 
+              Przy wdrożeniu CMS lub wyświetlaniu treści od użytkowników wymagane będzie sanitizowanie HTML na serwerze. */}
           <div dangerouslySetInnerHTML={{ __html: post.content }} />
         </div>
 
diff --git a/app/cennik-montazu/page.tsx b/app/cennik-montazu/page.tsx
index b665ff7..732acdd 100644
--- a/app/cennik-montazu/page.tsx
+++ b/app/cennik-montazu/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import Image from 'next/image';
 import { Check, Phone, ArrowRight, Wrench, Zap, Wind } from 'lucide-react';
@@ -111,7 +112,7 @@ export default function CennikMontazuPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="relative text-white py-24 md:py-32 overflow-hidden">
diff --git a/app/klimatyzacja-do-biura/page.tsx b/app/klimatyzacja-do-biura/page.tsx
index 9be6059..f1d6b8d 100644
--- a/app/klimatyzacja-do-biura/page.tsx
+++ b/app/klimatyzacja-do-biura/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import Image from 'next/image';
 import { Check, Phone, Wrench, ArrowRight, Building2, Thermometer, Wind, Zap, Clock } from 'lucide-react';
@@ -108,7 +109,7 @@ export default function KlimatyzacjaDoBiuraPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="relative text-white py-24 md:py-32 overflow-hidden">
diff --git a/app/klimatyzacja-do-domu/page.tsx b/app/klimatyzacja-do-domu/page.tsx
index 4376adb..b1491a1 100644
--- a/app/klimatyzacja-do-domu/page.tsx
+++ b/app/klimatyzacja-do-domu/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import Image from 'next/image';
 import { Phone, Wrench, ArrowRight, Home, Thermometer, Wind, Zap } from 'lucide-react';
@@ -86,7 +87,7 @@ export default function KlimatyzacjaDoDomuPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="relative text-white py-24 md:py-32 overflow-hidden">
diff --git a/app/klimatyzacja/[miasto]/page.tsx b/app/klimatyzacja/[miasto]/page.tsx
index f54f877..44e354c 100644
--- a/app/klimatyzacja/[miasto]/page.tsx
+++ b/app/klimatyzacja/[miasto]/page.tsx
@@ -1,4 +1,5 @@
 import { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import { notFound } from 'next/navigation';
 import Link from 'next/link';
 import { Clock, Phone, ArrowRight } from 'lucide-react';
@@ -63,10 +64,7 @@ export default async function MiastoPage({ params }: Props) {
 
   return (
     <main>
-      <script
-        type="application/ld+json"
-        dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }}
-      />
+      <JsonLd data={jsonLd} />
 
       {/* HERO */}
       <HeroSection
diff --git a/app/klimatyzacja/page.tsx b/app/klimatyzacja/page.tsx
index 6279ec5..e73230f 100644
--- a/app/klimatyzacja/page.tsx
+++ b/app/klimatyzacja/page.tsx
@@ -1,4 +1,5 @@
 import { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import { HeroSection } from '@/components/sections/HeroSection';
 import { InfoHighlights } from '@/components/sections/InfoHighlights';
 import { AcTypesSection } from '@/components/sections/AcTypesSection';
@@ -71,7 +72,7 @@ export default function KlimatyzacjaPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(faqJsonLd) }} />
+      <JsonLd data={faqJsonLd} />
       <main>
       <HeroSection
         eyebrow="15+ lat doświadczenia · Split i multisplit · Uprawnienia F-gaz"
diff --git a/app/klimatyzacja/wroclaw/[dzielnica]/page.tsx b/app/klimatyzacja/wroclaw/[dzielnica]/page.tsx
index f468f58..0678410 100644
--- a/app/klimatyzacja/wroclaw/[dzielnica]/page.tsx
+++ b/app/klimatyzacja/wroclaw/[dzielnica]/page.tsx
@@ -1,4 +1,5 @@
 import { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import { notFound } from 'next/navigation';
 import Link from 'next/link';
 import { MapPin, Clock, Phone, ArrowRight } from 'lucide-react';
@@ -67,10 +68,7 @@ export default async function DzielnicaPage({ params }: Props) {
 
   return (
     <main>
-      <script
-        type="application/ld+json"
-        dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }}
-      />
+      <JsonLd data={jsonLd} />
 
       <HeroSection
         eyebrow={`Klimatyzacja ${district.name} · Wrocław · F-Gaz`}
diff --git a/app/kontakt/actions.ts b/app/kontakt/actions.ts
index 90d02a9..ab67578 100644
--- a/app/kontakt/actions.ts
+++ b/app/kontakt/actions.ts
@@ -6,7 +6,6 @@ import { verifyRecaptcha } from "@/lib/recaptcha";
 
 const resend = new Resend(process.env.RESEND_API_KEY);
 
-// Schemat walidacji zgodny z tym po stronie klienta
 const contactFormSchema = z.object({
   name: z.string().min(2, "Imię musi mieć min. 2 znaki"),
   phone: z.string().min(9, "Wprowadź poprawny numer telefonu"),
@@ -30,7 +29,7 @@ export async function submitContactForm(prevState: unknown, formData: FormData)
       }
     }
 
-    // 1. Walidacja danych z formularza
+
     const rawData = {
       name: formData.get("name"),
       phone: formData.get("phone"),
@@ -106,7 +105,6 @@ export async function submitContactForm(prevState: unknown, formData: FormData)
 
     console.log("Wysłano e-mail (ID):", data?.id);
 
-    // 3. Zwrotka o sukcesie
     return {
       success: true,
       message: "Dziękujemy za wiadomość! Skontaktujemy się z Tobą najszybciej jak to możliwe.",
diff --git a/app/montaz-klimatyzacji/page.tsx b/app/montaz-klimatyzacji/page.tsx
index f8641dd..87cb664 100644
--- a/app/montaz-klimatyzacji/page.tsx
+++ b/app/montaz-klimatyzacji/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import Image from 'next/image';
 import { Check, Phone, Wrench, ArrowRight, ShieldCheck, Clock, Star } from 'lucide-react';
@@ -87,7 +88,7 @@ export default function MontazKlimatyzacjiPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="relative text-white py-24 md:py-32 overflow-hidden">
diff --git a/app/pompy-ciepla/page.tsx b/app/pompy-ciepla/page.tsx
index 7d257a0..41cb45b 100644
--- a/app/pompy-ciepla/page.tsx
+++ b/app/pompy-ciepla/page.tsx
@@ -1,4 +1,5 @@
 import { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import { HeroSection } from '@/components/sections/HeroSection';
 import { BenefitsGrid } from '@/components/sections/BenefitsGrid';
 import { HeatPumpTypes } from '@/components/sections/HeatPumpTypes';
@@ -70,7 +71,7 @@ export default function PompyCieplaPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(faqPompyJsonLd) }} />
+      <JsonLd data={faqPompyJsonLd} />
       <main>
       <HeroSection
         title="Pompy ciepła — niższe rachunki, niezależność, dofinansowanie"
diff --git a/app/serwis-daikin/page.tsx b/app/serwis-daikin/page.tsx
index c940bb1..4cec75e 100644
--- a/app/serwis-daikin/page.tsx
+++ b/app/serwis-daikin/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import { Check, Phone, Wrench, AlertTriangle, ArrowRight } from 'lucide-react';
 import { companyDetails } from '@/content/company';
@@ -72,7 +73,7 @@ export default function SerwisDaikinPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="bg-primary text-white py-16 md:py-24">
diff --git a/app/serwis-klimatyzacji/page.tsx b/app/serwis-klimatyzacji/page.tsx
index 7d7d0bc..d776307 100644
--- a/app/serwis-klimatyzacji/page.tsx
+++ b/app/serwis-klimatyzacji/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import Image from 'next/image';
 import { Check, Phone, Wrench, ArrowRight, Thermometer, Wind, Zap, ShieldCheck } from 'lucide-react';
@@ -120,7 +121,7 @@ export default function SerwisKlimatyzacjiPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="relative text-white py-24 md:py-32 overflow-hidden">
diff --git a/app/serwis-lg/page.tsx b/app/serwis-lg/page.tsx
index 2ffbbe3..bb10995 100644
--- a/app/serwis-lg/page.tsx
+++ b/app/serwis-lg/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import { Check, Phone, Wrench, AlertTriangle, ArrowRight } from 'lucide-react';
 import { companyDetails } from '@/content/company';
@@ -68,7 +69,7 @@ export default function SerwisLGPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="bg-primary text-white py-16 md:py-24">
diff --git a/app/serwis-mitsubishi/page.tsx b/app/serwis-mitsubishi/page.tsx
index d630797..832c81c 100644
--- a/app/serwis-mitsubishi/page.tsx
+++ b/app/serwis-mitsubishi/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import { Check, Phone, Wrench, AlertTriangle, ArrowRight } from 'lucide-react';
 import { companyDetails } from '@/content/company';
@@ -72,7 +73,7 @@ export default function SerwisMitsubishiPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="bg-primary text-white py-16 md:py-24">
diff --git a/app/serwis-samsung/page.tsx b/app/serwis-samsung/page.tsx
index 16bbe81..8703e40 100644
--- a/app/serwis-samsung/page.tsx
+++ b/app/serwis-samsung/page.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { JsonLd } from '@/components/ui/JsonLd';
 import Link from 'next/link';
 import { Check, Phone, Wrench, AlertTriangle, ArrowRight } from 'lucide-react';
 import { companyDetails } from '@/content/company';
@@ -72,7 +73,7 @@ export default function SerwisSamsungPage() {
 
   return (
     <>
-      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
+      <JsonLd data={jsonLd} />
       <main>
         {/* Hero */}
         <section className="bg-primary text-white py-16 md:py-24">
diff --git a/app/zamowienie/actions.ts b/app/zamowienie/actions.ts
index 816a8e1..ef37662 100644
--- a/app/zamowienie/actions.ts
+++ b/app/zamowienie/actions.ts
@@ -1,35 +1,46 @@
 'use server';
 
 import { z } from 'zod';
-import { Resend } from 'resend';
-import { verifyRecaptcha } from '@/lib/recaptcha';
+import { headers } from 'next/headers';
+import { getProductBySlug } from '@/content/products';
+import { escapeHtml, rateLimit, verifyRecaptcha, baseContactSchema } from '@/lib/security';
+import { getMailClient } from '@/lib/mail';
 
-const resend = new Resend(process.env.RESEND_API_KEY);
-
-const orderSchema = z.object({
-  name: z.string().min(2),
-  phone: z.string().min(9),
-  email: z.string().email(),
+const orderSchema = baseContactSchema.extend({
   address: z.string().optional(),
   notes: z.string().optional(),
-  consent: z.string(),
   products: z.string(),
-  total: z.string(),
+  total: z.string(), // We don't trust this total, just checking if it exists
 });
 
+const productItemSchema = z.array(z.object({
+  slug: z.string(),
+  quantity: z.number().int().min(1).max(100),
+}));
+
 export async function submitOrderForm(prevState: unknown, formData: FormData) {
   try {
+    const ip = (await headers()).get('x-forwarded-for') || 'unknown';
+    if (!rateLimit(ip)) {
+      return { success: false, message: 'Wysłano zbyt wiele zapytań. Spróbuj ponownie później.' };
+    }
+
     if (process.env.NEXT_PUBLIC_RECAPTCHA_SITE_KEY && process.env.RECAPTCHA_SECRET_KEY) {
       const token = formData.get('recaptchaToken') as string;
       if (!token) {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
-      const { success } = await verifyRecaptcha(token);
+      const success = await verifyRecaptcha(token);
       if (!success) {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
     }
 
+    const mailClient = getMailClient();
+    if (!mailClient) {
+      return { success: false, message: "Funkcja wysyłania wiadomości jest tymczasowo niedostępna." };
+    }
+
     const data = orderSchema.parse({
       name: formData.get('name'),
       phone: formData.get('phone'),
@@ -41,18 +52,44 @@ export async function submitOrderForm(prevState: unknown, formData: FormData) {
       total: formData.get('total'),
     });
 
-    const products = JSON.parse(data.products);
-    const total = parseFloat(data.total);
+    let rawProducts;
+    try {
+      rawProducts = JSON.parse(data.products);
+    } catch {
+      return { success: false, message: "Błąd przetwarzania koszyka." };
+    }
 
-    const productRows = products.map((p: { name: string; quantity: number; price: number }) =>
-      `<tr><td style="padding:8px;border-bottom:1px solid #f1f5f9;">${p.name}</td><td style="padding:8px;border-bottom:1px solid #f1f5f9;text-align:center;">${p.quantity}</td><td style="padding:8px;border-bottom:1px solid #f1f5f9;text-align:right;">${(p.price * p.quantity).toLocaleString('pl-PL')} zł</td></tr>`
+    const parsedProducts = productItemSchema.parse(rawProducts);
+    
+    if (parsedProducts.length === 0) {
+      return { success: false, message: "Koszyk jest pusty." };
+    }
+
+    let calculatedTotal = 0;
+    const validatedProducts = [];
+
+    for (const p of parsedProducts) {
+      const dbProduct = getProductBySlug(p.slug);
+      if (!dbProduct || !dbProduct.price) {
+        return { success: false, message: "Jeden z produktów w koszyku jest niedostępny." };
+      }
+      validatedProducts.push({
+        name: dbProduct.name,
+        quantity: p.quantity,
+        price: dbProduct.price
+      });
+      calculatedTotal += dbProduct.price * p.quantity;
+    }
+
+    const productRows = validatedProducts.map(p =>
+      `<tr><td style="padding:8px;border-bottom:1px solid #f1f5f9;">${escapeHtml(p.name)}</td><td style="padding:8px;border-bottom:1px solid #f1f5f9;text-align:center;">${p.quantity}</td><td style="padding:8px;border-bottom:1px solid #f1f5f9;text-align:right;">${(p.price * p.quantity).toLocaleString('pl-PL')} zł</td></tr>`
     ).join('');
 
-    await resend.emails.send({
-      from: process.env.RESEND_FROM_EMAIL || 'noreply@thermcool.pl',
-      to: process.env.RESEND_TO_EMAIL || 'biuro@thermcool.pl',
+    await mailClient.resend.emails.send({
+      from: mailClient.fromEmail,
+      to: mailClient.toEmail,
       replyTo: data.email,
-      subject: `Nowe zamówienie od ${data.name} — ${total.toLocaleString('pl-PL')} zł`,
+      subject: `Nowe zamówienie od ${escapeHtml(data.name)} — ${calculatedTotal.toLocaleString('pl-PL')} zł`,
       html: `
         <div style="font-family:Arial,sans-serif;max-width:600px;margin:0 auto;">
           <div style="background:#0F2A47;padding:20px;text-align:center;">
@@ -60,11 +97,11 @@ export async function submitOrderForm(prevState: unknown, formData: FormData) {
           </div>
           <div style="padding:24px;">
             <h2 style="font-size:16px;margin-top:0;">Dane klienta</h2>
-            <p><strong>Imię:</strong> ${data.name}</p>
-            <p><strong>Telefon:</strong> <a href="tel:${data.phone}">${data.phone}</a></p>
-            <p><strong>Email:</strong> ${data.email}</p>
-            ${data.address ? `<p><strong>Adres:</strong> ${data.address}</p>` : ''}
-            ${data.notes ? `<p><strong>Uwagi:</strong> ${data.notes}</p>` : ''}
+            <p><strong>Imię:</strong> ${escapeHtml(data.name)}</p>
+            <p><strong>Telefon:</strong> <a href="tel:${escapeHtml(data.phone)}">${escapeHtml(data.phone)}</a></p>
+            <p><strong>Email:</strong> ${escapeHtml(data.email)}</p>
+            ${data.address ? `<p><strong>Adres:</strong> ${escapeHtml(data.address)}</p>` : ''}
+            ${data.notes ? `<p><strong>Uwagi:</strong> ${escapeHtml(data.notes)}</p>` : ''}
             <h2 style="font-size:16px;">Zamówione produkty</h2>
             <table style="width:100%;border-collapse:collapse;">
               <thead><tr style="background:#f8fafc;">
@@ -75,7 +112,7 @@ export async function submitOrderForm(prevState: unknown, formData: FormData) {
               <tbody>${productRows}</tbody>
               <tfoot><tr>
                 <td colspan="2" style="padding:8px;font-weight:bold;">Łącznie (urządzenia)</td>
-                <td style="padding:8px;font-weight:bold;text-align:right;">${total.toLocaleString('pl-PL')} zł</td>
+                <td style="padding:8px;font-weight:bold;text-align:right;">${calculatedTotal.toLocaleString('pl-PL')} zł</td>
               </tr></tfoot>
             </table>
             <p style="margin-top:16px;font-size:12px;color:#64748b;">+ koszt montażu do ustalenia telefonicznie</p>
@@ -86,6 +123,6 @@ export async function submitOrderForm(prevState: unknown, formData: FormData) {
 
     return { success: true, message: 'Dziękujemy! Skontaktujemy się z Tobą w ciągu 24 godzin, aby potwierdzić zamówienie i ustalić termin montażu.' };
   } catch {
-    return { success: false, message: 'Wystąpił błąd. Spróbuj ponownie lub zadzwoń do nas bezpośrednio.' };
+    return { success: false, message: 'Wystąpił błąd podczas wysyłania zamówienia. Spróbuj ponownie.' };
   }
 }
diff --git a/app/zapytanie-multisplit/actions.ts b/app/zapytanie-multisplit/actions.ts
index d0e68b6..2134662 100644
--- a/app/zapytanie-multisplit/actions.ts
+++ b/app/zapytanie-multisplit/actions.ts
@@ -1,118 +1,102 @@
 "use server";
 
 import { z } from "zod";
-import { Resend } from "resend";
-import { verifyRecaptcha } from "@/lib/recaptcha";
+import { headers } from "next/headers";
+import { escapeHtml, rateLimit, verifyRecaptcha, baseContactSchema } from "@/lib/security";
+import { getMailClient } from "@/lib/mail";
 
-const resend = new Resend(process.env.RESEND_API_KEY);
-
-const multisplitFormSchema = z.object({
-  name: z.string().min(2, "Imię musi mieć min. 2 znaki"),
-  phone: z.string().min(9, "Wprowadź poprawny numer telefonu"),
-  email: z.union([z.literal(''), z.string().email("Niepoprawny adres e-mail")]).optional(),
+const multisplitFormSchema = baseContactSchema.extend({
   city: z.string().min(1, "Wybierz miasto"),
   rooms: z.string().optional(),
   message: z.string().optional(),
-  consent: z.boolean().refine((val) => val === true, "Zgoda RODO jest wymagana"),
   productName: z.string(),
   productSku: z.string(),
+  recaptchaToken: z.string().optional(),
 });
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-export async function submitMultisplitForm(data: Record<string, any>) {
+export async function submitMultisplitForm(data: Record<string, unknown>) {
   try {
+    const ip = (await headers()).get('x-forwarded-for') || 'unknown';
+    if (!rateLimit(ip)) {
+      return { success: false, message: 'Wysłano zbyt wiele zapytań. Spróbuj ponownie później.' };
+    }
+
     if (process.env.NEXT_PUBLIC_RECAPTCHA_SITE_KEY && process.env.RECAPTCHA_SECRET_KEY) {
-      if (!data.recaptchaToken) {
+      if (!data.recaptchaToken || typeof data.recaptchaToken !== 'string') {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
-      const { success } = await verifyRecaptcha(data.recaptchaToken);
+      const success = await verifyRecaptcha(data.recaptchaToken);
       if (!success) {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
     }
 
-    const validatedData = multisplitFormSchema.parse(data);
+    const mailClient = getMailClient();
+    if (!mailClient) {
+      return { success: false, message: "Funkcja wysyłania wiadomości jest tymczasowo niedostępna." };
+    }
 
-    const { error } = await resend.emails.send({
-      from: process.env.RESEND_FROM_EMAIL || "noreply@thermcool.pl",
-      to: process.env.RESEND_TO_EMAIL || "biuro@thermcool.pl",
+    // Convert boolean consent to string for base schema compatibility if it comes as boolean
+    const processData = { ...data };
+    if (typeof processData.consent === 'boolean') {
+      processData.consent = processData.consent ? "true" : "false";
+    }
+
+    const validatedData = multisplitFormSchema.parse(processData);
+
+    const { error } = await mailClient.resend.emails.send({
+      from: mailClient.fromEmail,
+      to: mailClient.toEmail,
       replyTo: validatedData.email || undefined,
-      subject: `Zapytanie o multisplit: ${validatedData.productName} (${validatedData.productSku})`,
+      subject: `Zapytanie o multisplit: ${escapeHtml(validatedData.productName)} (${escapeHtml(validatedData.productSku)})`,
       html: `
         <div style="font-family: Arial, sans-serif; max-width: 600px; margin: 0 auto; border: 1px solid #e5e7eb; border-radius: 8px; overflow: hidden; background-color: #ffffff;">
           <div style="background-color: #0F2A47; padding: 20px; text-align: center;">
             <h1 style="color: #ffffff; margin: 0; font-size: 24px;">Zapytanie o multisplit</h1>
-            <p style="color: #2BA8E0; margin: 5px 0 0 0; font-size: 14px;">Domena: thermcool.pl</p>
           </div>
           <div style="padding: 24px; color: #1e293b;">
-            <h2 style="font-size: 18px; margin-top: 0; border-bottom: 2px solid #f1f5f9; padding-bottom: 10px;">Dane kontaktowe:</h2>
             <table style="width: 100%; border-collapse: collapse; margin-bottom: 20px;">
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9; width: 120px;"><strong>Imię:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${validatedData.name}</td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.name)}</td>
               </tr>
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><strong>Telefon:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><a href="tel:${validatedData.phone}" style="color: #0F2A47; text-decoration: none;">${validatedData.phone}</a></td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.phone)}</td>
               </tr>
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><strong>E-mail:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><a href="mailto:${validatedData.email}" style="color: #0F2A47; text-decoration: none;">${validatedData.email || 'Brak'}</a></td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.email || 'Brak')}</td>
               </tr>
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><strong>Miasto:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${validatedData.city}</td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.city)}</td>
               </tr>
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><strong>Produkt:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${validatedData.productName} (${validatedData.productSku})</td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.productName)} (${escapeHtml(validatedData.productSku)})</td>
               </tr>
               <tr>
                 <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;"><strong>Pokoje:</strong></td>
-                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${validatedData.rooms}</td>
+                <td style="padding: 8px 0; border-bottom: 1px solid #f1f5f9;">${escapeHtml(validatedData.rooms || '')}</td>
               </tr>
             </table>
 
             <h2 style="font-size: 18px; border-bottom: 2px solid #f1f5f9; padding-bottom: 10px;">Dodatkowe informacje:</h2>
             <div style="background-color: #f8fafc; padding: 15px; border-radius: 6px; font-size: 15px; line-height: 1.6; white-space: pre-wrap;">
-              ${validatedData.message || 'Brak'}
+              ${escapeHtml(validatedData.message || 'Brak')}
             </div>
-
-            <p style="margin-top: 24px; font-size: 12px; color: #64748b; text-align: center;">
-              Zgoda RODO została zaakceptowana: <strong>${validatedData.consent ? "Tak" : "Nie"}</strong>
-            </p>
-          </div>
-          <div style="background-color: #f1f5f9; padding: 15px; text-align: center; font-size: 12px; color: #64748b;">
-            Wiadomość wygenerowana automatycznie z formularza multisplit na stronie thermcool.pl
           </div>
         </div>
       `,
     });
 
     if (error) {
-      console.error("Resend Error:", error);
-      return {
-        success: false,
-        message: "Nie udało się wysłać wiadomości ze względu na błąd serwera pocztowego.",
-      };
+      return { success: false, message: "Wystąpił problem z wysłaniem. Spróbuj ponownie." };
     }
 
-    return {
-      success: true,
-      message: "Dziękujemy za zapytanie! Skontaktujemy się z Tobą najszybciej jak to możliwe.",
-    };
+    return { success: true, message: "Dziękujemy za zapytanie! Skontaktujemy się z Tobą najszybciej jak to możliwe." };
   } catch (error) {
-    if (error instanceof z.ZodError) {
-      return {
-        success: false,
-        message: "Wystąpił błąd walidacji. Sprawdź poprawność danych.",
-        errors: error.flatten().fieldErrors,
-      };
-    }
-
-    return {
-      success: false,
-      message: "Wystąpił nieoczekiwany błąd serwera. Spróbuj ponownie później.",
-    };
+    return { success: false, message: "Błąd walidacji lub błąd serwera. Spróbuj ponownie później." };
   }
 }
diff --git a/app/zgloszenie-awarii/actions.ts b/app/zgloszenie-awarii/actions.ts
index ae43a93..6370a68 100644
--- a/app/zgloszenie-awarii/actions.ts
+++ b/app/zgloszenie-awarii/actions.ts
@@ -1,71 +1,87 @@
 'use server';
 
-import { Resend } from 'resend';
-import { verifyRecaptcha } from '@/lib/recaptcha';
+import { z } from 'zod';
+import { headers } from "next/headers";
+import { escapeHtml, rateLimit, verifyRecaptcha, baseContactSchema } from "@/lib/security";
+import { getMailClient } from "@/lib/mail";
 
-const resend = new Resend(process.env.RESEND_API_KEY);
+const awariaFormSchema = baseContactSchema.omit({ consent: true }).extend({
+  isUrgent: z.boolean().optional(),
+  brand: z.string().min(1, "Wymagana nazwa urządzenia"),
+  model: z.string().optional(),
+  errorCode: z.string().optional(),
+  problemType: z.string().optional(),
+  description: z.string().optional(),
+  warranty: z.string().optional(),
+  lastService: z.string().optional(),
+  city: z.string().min(1, "Wymagane miasto"),
+  preferredDate: z.string().optional(),
+  preferredTime: z.string().optional(),
+  recaptchaToken: z.string().optional(),
+});
 
-export async function submitAwariaForm(data: {
-  isUrgent: boolean;
-  brand: string;
-  model: string;
-  errorCode: string;
-  problemType: string;
-  description: string;
-  warranty: string;
-  lastService: string;
-  name: string;
-  phone: string;
-  city: string;
-  preferredDate: string;
-  preferredTime: string;
-  recaptchaToken?: string;
-}) {
+export async function submitAwariaForm(data: Record<string, unknown>) {
   try {
+    const ip = (await headers()).get('x-forwarded-for') || 'unknown';
+    if (!rateLimit(ip)) {
+      return { success: false, message: 'Wysłano zbyt wiele zapytań. Spróbuj ponownie później.' };
+    }
+
     if (process.env.NEXT_PUBLIC_RECAPTCHA_SITE_KEY && process.env.RECAPTCHA_SECRET_KEY) {
-      if (!data.recaptchaToken) {
+      if (!data.recaptchaToken || typeof data.recaptchaToken !== 'string') {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
-      const { success } = await verifyRecaptcha(data.recaptchaToken);
+      const success = await verifyRecaptcha(data.recaptchaToken);
       if (!success) {
         return { success: false, message: "Weryfikacja bezpieczeństwa nie powiodła się. Odśwież stronę i spróbuj ponownie." };
       }
     }
 
-    await resend.emails.send({
-      from: process.env.RESEND_FROM_EMAIL || 'noreply@thermcool.pl',
-      to: process.env.RESEND_TO_EMAIL || 'biuro@thermcool.pl',
-      subject: `${data.isUrgent ? '🚨 PILNE — ' : ''}Zgłoszenie serwisowe: ${data.brand} — ${data.city}`,
+    const mailClient = getMailClient();
+    if (!mailClient) {
+      return { success: false, message: "Funkcja wysyłania wiadomości jest tymczasowo niedostępna." };
+    }
+
+    // Default missing fields for zod validation
+    const parsedData = awariaFormSchema.parse({
+      ...data,
+      email: data.email || 'brak@email.pl', 
+    });
+
+    await mailClient.resend.emails.send({
+      from: mailClient.fromEmail,
+      to: mailClient.toEmail,
+      subject: `${parsedData.isUrgent ? '🚨 PILNE — ' : ''}Zgłoszenie serwisowe: ${escapeHtml(parsedData.brand)} — ${escapeHtml(parsedData.city)}`,
       html: `
         <div style="font-family:Arial,sans-serif;max-width:600px;margin:0 auto;">
-          <div style="background:${data.isUrgent ? '#ef4444' : '#0F2A47'};padding:20px;text-align:center;">
+          <div style="background:${parsedData.isUrgent ? '#ef4444' : '#0F2A47'};padding:20px;text-align:center;">
             <h1 style="color:#fff;margin:0;font-size:20px;">
-              ${data.isUrgent ? '🚨 PILNE — ' : ''}Zgłoszenie serwisowe ThermCool
+              ${parsedData.isUrgent ? '🚨 PILNE — ' : ''}Zgłoszenie serwisowe ThermCool
             </h1>
           </div>
           <div style="padding:24px;">
             <h2 style="font-size:16px;margin-top:0;">Dane klienta</h2>
-            <p><strong>Imię:</strong> ${data.name}</p>
-            <p><strong>Telefon:</strong> <a href="tel:${data.phone}">${data.phone}</a></p>
-            <p><strong>Miasto:</strong> ${data.city}</p>
-            ${data.preferredDate ? `<p><strong>Preferowany termin:</strong> ${data.preferredDate} ${data.preferredTime || ''}</p>` : ''}
+            <p><strong>Imię:</strong> ${escapeHtml(parsedData.name)}</p>
+            <p><strong>Telefon:</strong> <a href="tel:${escapeHtml(parsedData.phone)}">${escapeHtml(parsedData.phone)}</a></p>
+            <p><strong>Miasto:</strong> ${escapeHtml(parsedData.city)}</p>
+            ${parsedData.preferredDate ? `<p><strong>Preferowany termin:</strong> ${escapeHtml(parsedData.preferredDate)} ${escapeHtml(parsedData.preferredTime || '')}</p>` : ''}
 
             <h2 style="font-size:16px;">Urządzenie</h2>
-            <p><strong>Marka:</strong> ${data.brand}</p>
-            ${data.model ? `<p><strong>Model:</strong> ${data.model}</p>` : ''}
-            ${data.warranty ? `<p><strong>Gwarancja:</strong> ${data.warranty}</p>` : ''}
-            ${data.lastService ? `<p><strong>Ostatni serwis:</strong> ${data.lastService}</p>` : ''}
+            <p><strong>Marka:</strong> ${escapeHtml(parsedData.brand)}</p>
+            ${parsedData.model ? `<p><strong>Model:</strong> ${escapeHtml(parsedData.model)}</p>` : ''}
+            ${parsedData.warranty ? `<p><strong>Gwarancja:</strong> ${escapeHtml(parsedData.warranty)}</p>` : ''}
+            ${parsedData.lastService ? `<p><strong>Ostatni serwis:</strong> ${escapeHtml(parsedData.lastService)}</p>` : ''}
 
             <h2 style="font-size:16px;">Problem</h2>
-            <p><strong>Typ problemu:</strong> ${data.problemType}</p>
-            ${data.errorCode ? `<p><strong>Kod błędu:</strong> ${data.errorCode}</p>` : ''}
-            ${data.description ? `<p><strong>Opis:</strong> ${data.description}</p>` : ''}
+            <p><strong>Typ problemu:</strong> ${escapeHtml(parsedData.problemType || '')}</p>
+            ${parsedData.errorCode ? `<p><strong>Kod błędu:</strong> ${escapeHtml(parsedData.errorCode)}</p>` : ''}
+            ${parsedData.description ? `<p><strong>Opis:</strong> ${escapeHtml(parsedData.description)}</p>` : ''}
           </div>
         </div>
       `,
     });
     return { success: true };
   } catch {
-    return { success: false };
+    return { success: false, message: 'Wystąpił błąd podczas wysyłania.' };
   }
 }
diff --git a/components/ui/JsonLd.tsx b/components/ui/JsonLd.tsx
index f953a16..e59f9a5 100644
--- a/components/ui/JsonLd.tsx
+++ b/components/ui/JsonLd.tsx
@@ -2,7 +2,7 @@ export function JsonLd({ data }: { data: Record<string, unknown> }) {
   return (
     <script
       type="application/ld+json"
-      dangerouslySetInnerHTML={{ __html: JSON.stringify(data) }}
+      dangerouslySetInnerHTML={{ __html: JSON.stringify(data).replace(/</g, "\\u003c") }}
     />
   );
 }
diff --git a/lib/mail.ts b/lib/mail.ts
new file mode 100644
index 0000000..5b14e1c
--- /dev/null
+++ b/lib/mail.ts
@@ -0,0 +1,17 @@
+import { Resend } from 'resend';
+
+export function getMailClient() {
+  const apiKey = process.env.RESEND_API_KEY;
+  const fromEmail = process.env.RESEND_FROM_EMAIL;
+  const toEmail = process.env.RESEND_TO_EMAIL;
+
+  if (!apiKey || !fromEmail || !toEmail) {
+    return null;
+  }
+
+  return {
+    resend: new Resend(apiKey),
+    fromEmail,
+    toEmail,
+  };
+}
diff --git a/lib/security.ts b/lib/security.ts
new file mode 100644
index 0000000..b67b813
--- /dev/null
+++ b/lib/security.ts
@@ -0,0 +1,60 @@
+import { z } from 'zod';
+
+export function escapeHtml(unsafe: string): string {
+  if (typeof unsafe !== 'string') return '';
+  return unsafe
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#039;');
+}
+
+const rateLimitMap = new Map<string, { count: number; expiresAt: number }>();
+const MAX_REQUESTS = 5;
+const WINDOW_MS = 10 * 60 * 1000; // 10 minutes
+
+export function rateLimit(ip: string | undefined | null): boolean {
+  if (!ip) return true; // fallback if IP can't be resolved
+
+  const now = Date.now();
+  const entry = rateLimitMap.get(ip);
+
+  if (!entry || entry.expiresAt < now) {
+    rateLimitMap.set(ip, { count: 1, expiresAt: now + WINDOW_MS });
+    return true;
+  }
+
+  if (entry.count >= MAX_REQUESTS) {
+    return false;
+  }
+
+  entry.count++;
+  return true;
+}
+
+export async function verifyRecaptcha(token: string): Promise<boolean> {
+  const secretKey = process.env.RECAPTCHA_SECRET_KEY;
+  if (!secretKey) return false;
+
+  try {
+    const res = await fetch(`https://www.google.com/recaptcha/api/siteverify`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/x-www-form-urlencoded',
+      },
+      body: `secret=${secretKey}&response=${token}`,
+    });
+    const data = await res.json();
+    return data.success;
+  } catch (err) {
+    return false;
+  }
+}
+
+export const baseContactSchema = z.object({
+  name: z.string().min(2, "Imię musi mieć co najmniej 2 znaki").max(100, "Imię jest zbyt długie"),
+  phone: z.string().regex(/^[+\d\s-]{9,20}$/, "Niepoprawny format telefonu"),
+  email: z.string().email("Niepoprawny adres e-mail").max(150, "E-mail jest zbyt długi"),
+  consent: z.string().refine(val => val === "on" || val === "true", "Wymagana zgoda"),
+});
diff --git a/next.config.ts b/next.config.ts
index 81d45fb..f6a03fa 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -5,6 +5,21 @@ const withBundleAnalyzer = bundleAnalyzer({
   enabled: process.env.ANALYZE === 'true',
 });
 
+const cspHeader = `
+  default-src 'self';
+  script-src 'self' 'unsafe-eval' 'unsafe-inline' https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/ https://www.googletagmanager.com https://www.clarity.ms;
+  style-src 'self' 'unsafe-inline';
+  img-src 'self' blob: data: https://images.unsplash.com https://placehold.co https://c.bing.com https://www.google-analytics.com;
+  font-src 'self';
+  connect-src 'self' https://www.google-analytics.com https://*.clarity.ms;
+  frame-src 'self' https://www.google.com/recaptcha/ https://recaptcha.google.com/recaptcha/;
+  object-src 'none';
+  base-uri 'self';
+  form-action 'self';
+  frame-ancestors 'none';
+  upgrade-insecure-requests;
+`.replace(/\s{2,}/g, ' ').trim();
+
 const nextConfig: NextConfig = {
   experimental: {
     optimizeCss: true,
@@ -25,6 +40,9 @@ const nextConfig: NextConfig = {
           { key: 'X-Frame-Options', value: 'DENY' },
           { key: 'X-XSS-Protection', value: '1; mode=block' },
           { key: 'Referrer-Policy', value: 'strict-origin-when-cross-origin' },
+          { key: 'Content-Security-Policy', value: cspHeader },
+          { key: 'Strict-Transport-Security', value: 'max-age=31536000; includeSubDomains; preload' },
+          { key: 'Permissions-Policy', value: 'camera=(), microphone=(), geolocation=()' },
         ],
       },
     ];