/* ============================================
   Government AI Academy - Main Stylesheet
   Modern, Clean, Flat Design
   WCAG 2.1 AA Compliant
   ============================================ */

/* ============================================
   CSS Custom Properties (Design Tokens)
   ============================================ */
:root {
  /* Colors */
  --color-primary: #1e40af;
  --color-primary-light: #3b82f6;
  --color-primary-dark: #1e3a8a;
  --color-secondary: #0f766e;
  --color-secondary-light: #14b8a6;
  --color-dark: #0f172a;
  --color-light: #f8fafc;
  --color-white: #ffffff;
  --color-gray-50: #f8fafc;
  --color-gray-100: #f1f5f9;
  --color-gray-200: #e2e8f0;
  --color-gray-300: #cbd5e1;
  --color-gray-400: #94a3b8;
  --color-gray-500: #64748b;
  --color-gray-600: #475569;
  --color-gray-700: #334155;
  --color-gray-800: #1e293b;
  --color-gray-900: #0f172a;
  --color-success: #16a34a;
  --color-error: #dc2626;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-5: 1.25rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-10: 2.5rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;
  --spacing-20: 5rem;
  --spacing-24: 6rem;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;

  /* Borders */
  --border-radius-sm: 0.25rem;
  --border-radius: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;

  /* Focus */
  --focus-ring: 0 0 0 3px rgba(59, 130, 246, 0.5);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-dark);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-light);
}

a:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
  border-radius: var(--border-radius-sm);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

button:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

/* ============================================
   Skip Link (Accessibility)
   ============================================ */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--spacing-4);
  padding: var(--spacing-3) var(--spacing-4);
  background-color: var(--color-primary);
  color: var(--color-white);
  font-weight: 600;
  border-radius: var(--border-radius);
  z-index: 9999;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--spacing-4);
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: var(--line-height-tight);
  color: var(--color-dark);
}

h1 {
  font-size: var(--font-size-4xl);
}

h2 {
  font-size: var(--font-size-3xl);
}

h3 {
  font-size: var(--font-size-2xl);
}

h4 {
  font-size: var(--font-size-xl);
}

h5 {
  font-size: var(--font-size-lg);
}

h6 {
  font-size: var(--font-size-base);
}

p {
  margin-bottom: var(--spacing-4);
}

.text-sm {
  font-size: var(--font-size-sm);
}

.text-lg {
  font-size: var(--font-size-lg);
}

.text-xl {
  font-size: var(--font-size-xl);
}

.text-gray {
  color: var(--color-gray-600);
}

.text-center {
  text-align: center;
}

/* ============================================
   Layout
   ============================================ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-4);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.section {
  padding: var(--spacing-16) 0;
}

.section-sm {
  padding: var(--spacing-12) 0;
}

.section-lg {
  padding: var(--spacing-24) 0;
}

/* ============================================
   Header
   ============================================ */
.header {
  position: sticky;
  top: 0;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  z-index: 1000;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-dark);
}

.logo:hover {
  color: var(--color-dark);
}

.logo-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
}

/* Navigation */
.nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-8);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--spacing-6);
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-700);
  padding: var(--spacing-2) 0;
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--spacing-2);
}

.mobile-menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-dark);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-6);
  font-size: var(--font-size-sm);
  font-weight: 600;
  border-radius: var(--border-radius);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

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

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

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

.btn-secondary:hover {
  background-color: var(--color-secondary-light);
  color: var(--color-white);
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}

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

.btn-lg {
  padding: var(--spacing-4) var(--spacing-8);
  font-size: var(--font-size-base);
}

.btn-sm {
  padding: var(--spacing-2) var(--spacing-4);
  font-size: var(--font-size-xs);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  background: linear-gradient(135deg, var(--color-gray-50) 0%, var(--color-white) 100%);
  padding: var(--spacing-20) 0;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-12);
  align-items: center;
}

.hero-content {
  max-width: 600px;
}

.hero-title {
  font-size: var(--font-size-5xl);
  margin-bottom: var(--spacing-6);
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-gray-600);
  margin-bottom: var(--spacing-8);
  line-height: var(--line-height-relaxed);
}

.hero-actions {
  display: flex;
  gap: var(--spacing-4);
  flex-wrap: wrap;
}

.hero-image {
  position: relative;
}

.hero-image img {
  width: 100%;
  max-width: 500px;
  height: auto;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  animation: heroFloat 6s ease-in-out infinite;
}

@keyframes heroFloat {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* ============================================
   Cards
   ============================================ */
.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-6);
  transition: box-shadow var(--transition-normal), transform var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-4);
  color: var(--color-white);
}

.card-title {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-2);
}

.card-text {
  color: var(--color-gray-600);
  font-size: var(--font-size-sm);
  margin-bottom: 0;
}

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-6);
}

.card-grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* ============================================
   Section Headers
   ============================================ */
.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--spacing-12);
}

.section-header h2 {
  margin-bottom: var(--spacing-4);
}

.section-header p {
  color: var(--color-gray-600);
  font-size: var(--font-size-lg);
  margin-bottom: 0;
}

.section-label {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-2);
}

/* ============================================
   CTA Section
   ============================================ */
.cta-section {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: var(--color-white);
  text-align: center;
}

.cta-section h2 {
  color: var(--color-white);
  margin-bottom: var(--spacing-4);
}

.cta-section p {
  color: rgba(255, 255, 255, 0.9);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-8);
}

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

.cta-section .btn-primary:hover {
  background-color: var(--color-gray-100);
}

/* ============================================
   Forms
   ============================================ */
.form-group {
  margin-bottom: var(--spacing-4);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: var(--spacing-2);
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--font-size-base);
  font-family: inherit;
  color: var(--color-dark);
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--border-radius);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: var(--focus-ring);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-gray-400);
}

.form-textarea {
  min-height: 150px;
  resize: vertical;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-4);
}

.form-error {
  color: var(--color-error);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-1);
}

.form-success {
  background-color: #dcfce7;
  border: 1px solid var(--color-success);
  color: var(--color-success);
  padding: var(--spacing-4);
  border-radius: var(--border-radius);
  text-align: center;
  margin-bottom: var(--spacing-4);
}

/* Newsletter Form */
.newsletter-form {
  background-color: var(--color-gray-50);
  padding: var(--spacing-8);
  border-radius: var(--border-radius-lg);
  max-width: 600px;
  margin: 0 auto;
}

.newsletter-form h3 {
  margin-bottom: var(--spacing-2);
}

.newsletter-form p {
  color: var(--color-gray-600);
  margin-bottom: var(--spacing-6);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background-color: var(--color-gray-900);
  color: var(--color-gray-300);
  padding: var(--spacing-16) 0 var(--spacing-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-8);
  margin-bottom: var(--spacing-12);
}

.footer-brand {
  max-width: 300px;
}

.footer-brand .logo {
  color: var(--color-white);
  margin-bottom: var(--spacing-4);
}

.footer-brand p {
  font-size: var(--font-size-sm);
  color: var(--color-gray-400);
  margin-bottom: var(--spacing-4);
}

.footer-heading {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-white);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-4);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
}

.footer-links a {
  font-size: var(--font-size-sm);
  color: var(--color-gray-400);
}

.footer-links a:hover {
  color: var(--color-white);
}

.footer-social {
  display: flex;
  gap: var(--spacing-4);
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background-color: var(--color-gray-800);
  border-radius: var(--border-radius-full);
  color: var(--color-gray-400);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.footer-social a:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid var(--color-gray-800);
  padding-top: var(--spacing-8);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-4);
}

.footer-bottom p {
  font-size: var(--font-size-sm);
  color: var(--color-gray-300);
  margin-bottom: 0;
}

.footer-legal {
  display: flex;
  gap: var(--spacing-6);
}

.footer-legal a {
  font-size: var(--font-size-sm);
  color: var(--color-gray-300);
}

.footer-legal a:hover {
  color: var(--color-white);
}

/* ============================================
   Page Header (Inner Pages)
   ============================================ */
.page-header {
  background: linear-gradient(135deg, var(--color-gray-50) 0%, var(--color-white) 100%);
  padding: var(--spacing-16) 0;
  text-align: center;
}

.page-header h1 {
  margin-bottom: var(--spacing-4);
}

.page-header p {
  font-size: var(--font-size-lg);
  color: var(--color-gray-600);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================
   Content Sections
   ============================================ */
.content-section {
  padding: var(--spacing-16) 0;
}

.content-section:nth-child(even) {
  background-color: var(--color-gray-50);
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-12);
  align-items: center;
}

.content-grid.reverse {
  direction: rtl;
}

.content-grid.reverse > * {
  direction: ltr;
}

/* ============================================
   Feature List
   ============================================ */
.feature-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-4);
}

.feature-item {
  display: flex;
  gap: var(--spacing-4);
  align-items: flex-start;
}

.feature-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  color: var(--color-primary);
}

.feature-content h4 {
  margin-bottom: var(--spacing-1);
}

.feature-content p {
  color: var(--color-gray-600);
  font-size: var(--font-size-sm);
  margin-bottom: 0;
}

/* ============================================
   Info Box
   ============================================ */
.info-box {
  background-color: var(--color-primary);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: var(--color-white);
  padding: var(--spacing-6);
  border-radius: var(--border-radius-lg);
}

.info-box h3 {
  color: var(--color-white);
  margin-bottom: var(--spacing-2);
}

.info-box p {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 0;
}

/* ============================================
   Legal Pages
   ============================================ */
.legal-content {
  max-width: var(--container-narrow);
  margin: 0 auto;
}

.legal-content h2 {
  font-size: var(--font-size-2xl);
  margin-top: var(--spacing-10);
  margin-bottom: var(--spacing-4);
}

.legal-content h3 {
  font-size: var(--font-size-xl);
  margin-top: var(--spacing-8);
  margin-bottom: var(--spacing-3);
}

.legal-content p {
  color: var(--color-gray-700);
  line-height: var(--line-height-relaxed);
}

.legal-content ul {
  list-style: disc;
  padding-left: var(--spacing-6);
  margin-bottom: var(--spacing-4);
}

.legal-content li {
  color: var(--color-gray-700);
  margin-bottom: var(--spacing-2);
  line-height: var(--line-height-relaxed);
}

.legal-content a {
  text-decoration: underline;
}

.effective-date {
  color: var(--color-gray-500);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-8);
}

/* ============================================
   Contact Page
   ============================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-12);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-6);
}

.contact-item {
  display: flex;
  gap: var(--spacing-4);
  align-items: flex-start;
}

.contact-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  background-color: var(--color-primary);
  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
}

.contact-details h4 {
  margin-bottom: var(--spacing-1);
}

.contact-details p,
.contact-details a {
  color: var(--color-gray-600);
  margin-bottom: 0;
}

.contact-details a:hover {
  color: var(--color-primary);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .content-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
  }

  .content-grid.reverse {
    direction: ltr;
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.5rem;
    --font-size-4xl: 2rem;
    --font-size-3xl: 1.5rem;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    flex-direction: column;
    padding: var(--spacing-4);
    border-bottom: 1px solid var(--color-gray-200);
    box-shadow: var(--shadow-lg);
  }

  .nav-list.active {
    display: flex;
  }

  .nav-link {
    padding: var(--spacing-3) 0;
  }

  .mobile-menu-toggle {
    display: flex;
  }

  .hero {
    padding: var(--spacing-12) 0;
  }

  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-image {
    order: -1;
  }

  .hero-image img {
    max-width: 350px;
    margin: 0 auto;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .section {
    padding: var(--spacing-12) 0;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-8);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

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

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

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

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-4);
  }

  .hero-title {
    font-size: var(--font-size-3xl);
  }

  .btn-lg {
    padding: var(--spacing-3) var(--spacing-6);
    font-size: var(--font-size-sm);
  }
}

/* ============================================
   Utility Classes
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hidden {
  display: none !important;
}

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

.mb-4 {
  margin-bottom: var(--spacing-4);
}

.mb-8 {
  margin-bottom: var(--spacing-8);
}

.mt-4 {
  margin-top: var(--spacing-4);
}

.mt-8 {
  margin-top: var(--spacing-8);
}