:root {
  /* Light theme colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #64748b;
  --accent-primary: #6366f1;
  --accent-hover: #4f46e5;
  --border-color: #e2e8f0;
  --code-bg: #f1f5f9;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: background-color 0.3s ease, border-color 0.3s ease;
  overflow: hidden;
}

/* Header SVG background */
.header-bg-svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 140px;
  z-index: 0;
  pointer-events: none;
}

/* Non-home page header with gradient background */
.header:not(.header-overlay) {
  background: linear-gradient(135deg, #0c4a6e 0%, #075985 50%, #0e7490 100%);
  border-bottom: none;
}

.header:not(.header-overlay) .header-container {
  position: relative;
  z-index: 1;
}

/* Non-home page header text colors */
.header:not(.header-overlay) .logo {
  color: #ffffff;
}

.header:not(.header-overlay) .nav-links a {
  color: rgba(255, 255, 255, 0.9);
}

.header:not(.header-overlay) .nav-links a:hover,
.header:not(.header-overlay) .nav-links a.active {
  color: #a5b4fc;
}

.header:not(.header-overlay) .lang-switcher button {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.9);
}

.header:not(.header-overlay) .lang-switcher button.active {
  background-color: rgba(129, 140, 248, 0.8);
  color: white;
  border-color: rgba(129, 140, 248, 0.8);
}

.header:not(.header-overlay) .lang-switcher button:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
  color: white;
}

.header:not(.header-overlay) .mobile-menu-btn {
  color: rgba(255, 255, 255, 0.9);
  border-color: rgba(255, 255, 255, 0.2);
}

.header:not(.header-overlay) .mobile-menu-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: white;
}

/* Home page: no border on header */
.home-page .header {
  border-bottom: none;
  box-shadow: none;
}

/* Home page header overlay on carousel */
.home-page .header-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  background: transparent;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border-bottom: none;
  box-shadow: none;
  z-index: 100;
}

.home-page .header-overlay .logo {
  color: #ffffff;
}

.home-page .header-overlay .nav-links a {
  color: rgba(255, 255, 255, 0.9);
}

.home-page .header-overlay .nav-links a:hover,
.home-page .header-overlay .nav-links a.active {
  color: #a5b4fc;
}

.home-page .header-overlay .lang-switcher button {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.9);
}

.home-page .header-overlay .lang-switcher button.active {
  background-color: rgba(129, 140, 248, 0.8);
  color: white;
  border-color: rgba(129, 140, 248, 0.8);
}

.home-page .header-overlay .lang-switcher button:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
  color: white;
}

.home-page .header-overlay .mobile-menu-btn {
  color: rgba(255, 255, 255, 0.9);
  border-color: rgba(255, 255, 255, 0.2);
}

.home-page .header-overlay .mobile-menu-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: white;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1.25rem;
  transition: color 0.3s ease;
}

.logo img {
  height: 32px;
  width: auto;
}

.nav {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-primary);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--accent-primary);
}

.header-actions {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.btn {
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

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

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
}

.btn-icon {
  padding: 0.5rem;
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.btn-icon:hover {
  color: var(--text-primary);
  background-color: var(--bg-secondary);
}

/* Main content */
.main {
  min-height: calc(100vh - 200px);
}

/* Home page: no top margin for main since header is overlay */
.home-page .main {
  margin-top: 0;
  padding-top: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

/* Hero Carousel */
.hero-carousel {
  position: relative;
  width: 100%;
  height: 600px;
  overflow: hidden;
  background: var(--bg-primary);
  margin-top: 0;
}

/* Home page: carousel extends from top, covering header */
.home-page .hero-carousel {
  margin-top: -80px; /* Negative margin to start from top, covering header */
  padding-top: 80px; /* Padding to account for header */
  height: calc(600px + 80px); /* Extend height to include header */
}

.home-page .hero-background {
  position: absolute;
  top: 0; /* Start from top of hero-carousel */
  left: 0;
  width: 100%;
  height: 100%; /* Full height of hero-carousel */
  z-index: 0;
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.carousel-content {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  padding: 2rem;
  text-align: center;
  color: var(--text-primary);
}

/* Home page: adjust carousel content padding to account for header */
.home-page .carousel-content {
  padding-top: 2rem;
  margin-top: 80px; /* Offset for header height */
}

.carousel-content h2 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Home page: carousel text should be white/light */
.home-page .carousel-content h2 {
  background: linear-gradient(135deg, #ffffff 0%, #a5b4fc 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.carousel-content p {
  font-size: 1.5rem;
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 2rem;
  line-height: 1.8;
}

/* Home page: carousel text should be white/light */
.home-page .carousel-content p {
  color: rgba(255, 255, 255, 0.95);
}

.carousel-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

/* Slide 1: Big Data Visualization */
.slide-bigdata {
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 50%, #7e22ce 100%);
}

.slide-bigdata .carousel-background::before {
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(255,255,255,0.1) 0%, transparent 50%);
  opacity: 0.6;
}

/* Slide 2: AI & Machine Learning */
.slide-ai {
  background: linear-gradient(135deg, #0c4a6e 0%, #075985 50%, #0e7490 100%);
}

/* Slide 3: Cloud Native */
.slide-cloud {
  background: linear-gradient(135deg, #7c2d12 0%, #c2410c 50%, #dc2626 100%);
}

/* Slide 4: Data Flow */
.slide-dataflow {
  background: linear-gradient(135deg, #064e3b 0%, #065f46 50%, #047857 100%);
}

/* Data Visualization SVG Elements */
.data-visualization {
  width: 100%;
  height: 100%;
  display: block;
}

.home-page .hero-background .data-visualization {
  width: 100%;
  height: 100%;
  display: block;
}

/* Carousel controls removed */

.hero {
  text-align: center;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 3rem;
  line-height: 1.8;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.feature-card {
  background-color: var(--bg-secondary);
  padding: 2rem;
  border-radius: 1rem;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent-primary);
}

.feature-card h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.feature-list {
  list-style: none;
  margin: 1.5rem 0;
}

.feature-list li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 25px;
  text-align: left;
}

.feature-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
  font-weight: bold;
}

/* Features Showcase Section */
.features-showcase {
  padding: 5rem 0;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 1rem;
  color: var(--text-primary);
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  text-align: center;
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 4rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.feature-showcase-grid {
  display: flex;
  flex-direction: column;
}

.feature-row {
  display: flex;
  align-items: center;
  gap: 4rem;
}

.feature-row.reverse {
  flex-direction: row-reverse;
}

.feature-text {
  flex: 1;
  min-width: 0;
}

.feature-text h3 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.feature-text p {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1.125rem;
  margin: 0;
}

.feature-visual {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-visual svg {
  width: 100%;
  max-width: 400px;
  height: auto;
}

/* Legacy styles for backward compatibility (if needed elsewhere) */
.feature-showcase-item {
  background-color: var(--bg-secondary);
  padding: 2.5rem;
  border-radius: 1.5rem;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 3rem;
}

.feature-icon {
  width: 200px;
  height: 200px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
  border-radius: 50%;
  padding: 1.5rem;
  transition: all 0.3s ease;
}

.feature-showcase-item:hover .feature-icon {
  transform: scale(1.1);
  box-shadow: 0 8px 20px rgba(99, 102, 241, 0.2);
}

.feature-icon svg {
  width: 100%;
  height: 100%;
}

.feature-content {
  flex: 1;
  text-align: left;
}

.section {
  margin: 4rem 0;
}

.section h2 {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  color: var(--text-primary);
}

.section h3 {
  font-size: 1.75rem;
  margin: 2rem 0 1rem;
  color: var(--text-primary);
}

.section h4 {
  font-size: 1.25rem;
  margin: 1.5rem 0 0.75rem;
  color: var(--text-primary);
}

.section p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.8;
}

.section ul,
.section ol {
  margin: 1rem 0 1rem 2rem;
  color: var(--text-secondary);
}

.section li {
  margin: 0.5rem 0;
}

/* Code blocks */
pre {
  background-color: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}

code {
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.875rem;
  background-color: var(--code-bg);
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
  color: #dc2626;
}

pre code {
  background: none;
  padding: 0;
  color: var(--text-primary);
}

/* Images */
.section img {
  max-width: 100%;
  height: auto;
  border-radius: 0.5rem;
  margin: 1.5rem 0;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
}

/* Links */
a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color 0.3s ease;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Footer */
.footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 2rem 2rem;
  margin-top: 4rem;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section h4 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.footer-section ul {
  list-style: none;
  margin: 0;
}

.footer-section ul li {
  margin: 0.5rem 0;
}

.footer-section a {
  color: var(--text-secondary);
}

.footer-section a:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  margin-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

/* Mobile menu */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: 60px;
    left: 0;
    right: 0;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    padding: 1rem;
    gap: 0;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  /* Home page mobile menu */
  .home-page .nav-links {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: none;
  }

  .home-page .nav-links a {
    color: rgba(15, 23, 42, 0.9);
  }

  .home-page .nav-links a:hover,
  .home-page .nav-links a.active {
    color: #6366f1;
  }

  .nav-links li {
    width: 100%;
    padding: 0.75rem 0;
  }

  .nav-links a {
    display: block;
    padding: 0.5rem;
  }

  .hero-carousel {
    height: 500px;
  }

  .carousel-content h2 {
    font-size: 2rem;
  }

  .carousel-content p {
    font-size: 1.125rem;
  }

  /* Home page: adjust carousel content padding on mobile */
  .home-page .hero-carousel {
    padding-top: 60px;
    height: calc(500px + 60px);
  }

  .home-page .hero-background {
    top: -60px;
    height: calc(100% + 60px);
  }

  .home-page .carousel-content {
    padding-top: 1rem;
    margin-top: 60px;
  }

  .carousel-nav {
    width: 40px;
    height: 40px;
    font-size: 1.25rem;
  }

  .carousel-nav.prev {
    left: 1rem;
  }

  .carousel-nav.next {
    right: 1rem;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    font-size: 1rem;
  }

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

  .header-container {
    padding: 1rem;
  }

  .container {
    padding: 1rem;
  }

  .feature-row {
    flex-direction: column !important;
    gap: 2rem;
    padding: 2rem 0;
  }

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

  .feature-text h3 {
    font-size: 1.5rem;
  }

  .feature-text p {
    font-size: 1rem;
  }

  .feature-visual svg {
    max-width: 300px;
  }

  .feature-showcase-item {
    flex-direction: column !important;
    text-align: center;
    gap: 2rem;
  }

  .feature-icon {
    width: 150px;
    height: 150px;
  }

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

/* Language switcher */
.lang-switcher {
  display: flex;
  gap: 0.5rem;
}

.lang-switcher button {
  padding: 0.25rem 0.75rem;
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: 0.25rem;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 0.875rem;
}

.lang-switcher button.active {
  background-color: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
}

.lang-switcher button:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
}

/* Content sections */
.content-section {
  margin: 2rem 0;
  padding: 2rem;
  background-color: var(--bg-secondary);
  border-radius: 1rem;
  border: 1px solid var(--border-color);
}

.content-section h2 {
  margin-top: 0;
}

/* Utility classes */
.text-center {
  text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }