/* FLAT WHITE Design System */

/* ===== CSS Variables ===== */
:root {
  /* Kolory */
  --color-black: #000000;
  --color-white: #FFFFFF;
  --color-gray-light: #F5F5F5;
  --color-gray-medium: #CCCCCC;
  --color-gray-dark: #666666;

  /* Typografia - Desktop */
  --font-size-h1: 48px;
  --font-size-h2: 32px;
  --font-size-h3: 24px;
  --font-size-body: 18px;
  --font-size-small: 14px;

  /* Typografia - Mobile */
  --font-size-h1-mobile: 32px;
  --font-size-h2-mobile: 24px;
  --font-size-h3-mobile: 20px;
  --font-size-body-mobile: 16px;
  --font-size-small-mobile: 14px;

  /* Spacing (8px grid) */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;
  --spacing-4xl: 96px;

  /* Breakpoints */
  --breakpoint-sm: 640px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 1024px;
  --breakpoint-xl: 1280px;
}

/* ===== Reset & Base ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: var(--font-size-body-mobile);
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-black);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

@media (min-width: 768px) {
  body {
    font-size: var(--font-size-body);
  }
}

/* ===== Typography ===== */
h1, .h1 {
  font-size: var(--font-size-h1-mobile);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-lg);
}

@media (min-width: 768px) {
  h1, .h1 {
    font-size: var(--font-size-h1);
  }
}

h2, .h2 {
  font-size: var(--font-size-h2-mobile);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin-bottom: var(--spacing-md);
}

@media (min-width: 768px) {
  h2, .h2 {
    font-size: var(--font-size-h2);
  }
}

h3, .h3 {
  font-size: var(--font-size-h3-mobile);
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: var(--spacing-md);
}

@media (min-width: 768px) {
  h3, .h3 {
    font-size: var(--font-size-h3);
  }
}

p {
  margin-bottom: var(--spacing-md);
}

small, .small {
  font-size: var(--font-size-small);
  line-height: 1.5;
}

/* ===== Links ===== */
a {
  color: var(--color-black);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: opacity 0.2s ease;
}

a:hover {
  opacity: 0.7;
}

a:focus {
  outline: 2px solid var(--color-black);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ===== Buttons ===== */
.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  border: 2px solid var(--color-black);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s ease;
  min-height: 44px;
}

.btn-primary {
  background-color: var(--color-black);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: #333333;
  border-color: #333333;
  opacity: 1;
}

.btn-primary:active {
  transform: translateY(1px);
}

.btn-primary:focus {
  outline: 2px solid var(--color-black);
  outline-offset: 2px;
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-black);
}

.btn-secondary:hover {
  background-color: var(--color-black);
  color: var(--color-white);
  opacity: 1;
}

.btn-secondary:focus {
  outline: 2px solid var(--color-black);
  outline-offset: 2px;
}

.btn-large {
  padding: 18px 40px;
  font-size: 18px;
  min-height: 52px;
}

.btn-small {
  padding: 10px 24px;
  font-size: 14px;
  min-height: 36px;
}

/* ===== Forms ===== */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-black);
  margin-bottom: var(--spacing-sm);
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  font-size: 16px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--color-black);
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-medium);
  border-radius: 4px;
  transition: border-color 0.2s ease;
  min-height: 44px;
  font-family: inherit;
}

.form-input:focus {
  outline: none;
  border-color: var(--color-black);
  border-width: 2px;
  padding: 11px 15px;
}

.form-input::placeholder {
  color: var(--color-gray-dark);
  opacity: 1;
}

.form-input:disabled {
  background-color: var(--color-gray-light);
  cursor: not-allowed;
}

/* ===== Container ===== */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--spacing-xl);
  }
}

/* ===== Grid ===== */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-1 {
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ===== Header ===== */
.header {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-gray-medium);
  position: sticky;
  top: 0;
  background-color: var(--color-white);
  z-index: 100;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 20px;
  font-weight: 700;
  text-decoration: none;
  color: var(--color-black);
}

.nav-links {
  display: none;
  gap: var(--spacing-lg);
  list-style: none;
  margin: 0;
  padding: 0;
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  font-size: 16px;
  font-weight: 500;
  color: var(--color-black);
  text-decoration: none;
  transition: opacity 0.2s ease;
}

.nav-link:hover {
  opacity: 0.7;
}

/* ===== Hero Section ===== */
.hero {
  padding: var(--spacing-3xl) 0;
  text-align: center;
}

@media (min-width: 768px) {
  .hero {
    padding: var(--spacing-4xl) 0;
  }
}

.hero-title {
  font-size: var(--font-size-h1-mobile);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-lg);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: var(--font-size-h1);
  }
}

.hero-subtitle {
  font-size: var(--font-size-body-mobile);
  line-height: 1.6;
  margin-bottom: var(--spacing-xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  color: var(--color-gray-dark);
}

@media (min-width: 768px) {
  .hero-subtitle {
    font-size: var(--font-size-body);
  }
}

.hero-cta {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  align-items: center;
}

@media (min-width: 640px) {
  .hero-cta {
    flex-direction: row;
    justify-content: center;
  }
}

/* ===== Section ===== */
.section {
  padding: var(--spacing-3xl) 0;
}

.section-title {
  font-size: var(--font-size-h2-mobile);
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

@media (min-width: 768px) {
  .section-title {
    font-size: var(--font-size-h2);
    margin-bottom: var(--spacing-xl);
  }
}

.section-content {
  max-width: 800px;
  margin: 0 auto;
}

/* ===== Cards ===== */
.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-medium);
  border-radius: 8px;
  padding: var(--spacing-lg);
  transition: box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.card-title {
  font-size: var(--font-size-h3-mobile);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

@media (min-width: 768px) {
  .card-title {
    font-size: var(--font-size-h3);
  }
}

.card-body {
  margin-bottom: var(--spacing-md);
}

.card-footer {
  margin-top: var(--spacing-md);
}

/* ===== Badge ===== */
.badge {
  display: inline-block;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  line-height: 1.5;
  background-color: var(--color-gray-light);
  color: var(--color-black);
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-primary {
  background-color: var(--color-black);
  color: var(--color-white);
}

/* ===== Alert ===== */
.alert {
  padding: var(--spacing-md);
  border-radius: 4px;
  margin-bottom: var(--spacing-lg);
}

.alert-info {
  background-color: #EFF6FF;
  border-left: 4px solid #3B82F6;
  color: #1E40AF;
}

/* ===== Footer ===== */
.footer {
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
  border-top: 1px solid var(--color-gray-medium);
  margin-top: var(--spacing-4xl);
}

.footer-content {
  display: grid;
  gap: var(--spacing-xl);
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .footer-content {
    grid-template-columns: repeat(3, 1fr);
  }
}

.footer-section-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer-link {
  font-size: 14px;
  color: var(--color-gray-dark);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: var(--color-black);
}

/* ===== Utilities ===== */
.text-center {
  text-align: center;
}

.mb-0 {
  margin-bottom: 0;
}

.mt-xl {
  margin-top: var(--spacing-xl);
}