/* CSS Custom Properties - Color Palette */
:root {
  /* Base Colors */
  --color-black: #000000;
  --color-white: #ffffff;
  --color-dark-gray: #111111;
  --color-light-gray: #f8f9fa;
  --color-medium-gray: #6c757d;
  
  /* Accent Colors */
  --color-metallic-red: #dc2626;
  --color-metallic-red-hover: #b91c1c;
  --color-metallic-red-dark: #991b1b;
  --color-neon-white: #f0f9ff;
  --color-neon-white-glow: rgba(240, 249, 255, 0.8);
  
  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, 'Courier New', monospace;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Borders & Shadows */
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-normal: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  line-height: 1.6;
  color: var(--color-black);
  background-color: var(--color-white);
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

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

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

a:hover {
  color: var(--color-metallic-red-hover);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Header & Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-black);
}

.logo-sub {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-metallic-red);
  background: linear-gradient(135deg, var(--color-metallic-red), var(--color-metallic-red-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: var(--spacing-xl);
}

.nav-link {
  color: var(--color-black);
  font-weight: 500;
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-metallic-red);
  transition: width var(--transition-fast);
}

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

.nav-link.active {
  color: var(--color-metallic-red);
}

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

/* Hero Section */
.hero {
  padding: 120px 0 80px;
  background: linear-gradient(135deg, var(--color-white) 0%, var(--color-neon-white) 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-3xl);
  align-items: center;
}

.hero-title {
  font-size: 4rem;
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: var(--spacing-lg);
}

.hero-highlight {
  background: linear-gradient(135deg, var(--color-metallic-red), var(--color-metallic-red-dark));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  position: relative;
}

.hero-highlight::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--color-metallic-red), transparent);
  animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
  from { opacity: 0.5; }
  to { opacity: 1; }
}

.hero-description {
  font-size: 1.25rem;
  color: var(--color-medium-gray);
  margin-bottom: var(--spacing-xl);
  line-height: 1.6;
}

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--border-radius);
  font-family: var(--font-primary);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-metallic-red), var(--color-metallic-red-dark));
  color: var(--color-white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: linear-gradient(135deg, var(--color-metallic-red-hover), var(--color-metallic-red));
}

.btn-secondary {
  background: var(--color-white);
  color: var(--color-black);
  border: 2px solid var(--color-black);
}

.btn-secondary:hover {
  background: var(--color-black);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-large {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: 1.125rem;
}

.btn-icon {
  font-size: 1.25em;
}

.download-size {
  font-size: 0.875rem;
  opacity: 0.8;
  font-weight: 400;
}

/* Code Preview */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.code-preview {
  background: var(--color-dark-gray);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  width: 100%;
  max-width: 500px;
  animation: float 6s ease-in-out infinite;
}

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

.code-header {
  background: #1a1a1a;
  padding: var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #333;
}

.code-dots {
  display: flex;
  gap: var(--spacing-sm);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot.red { background: #ff5f57; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #28ca42; }

.code-title {
  color: var(--color-neon-white);
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

.code-content {
  padding: var(--spacing-lg);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.5;
}

.code-line {
  color: var(--color-neon-white);
  margin-bottom: var(--spacing-xs);
}

.code-comment { color: #6a9955; }
.code-keyword { color: #569cd6; }
.code-string { color: #ce9178; }

/* Sections */
.section-title {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-metallic-red), var(--color-metallic-red-dark));
  border-radius: 2px;
}

/* Features Section */
.features {
  padding: var(--spacing-3xl) 0;
  background: var(--color-white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-xl);
}

.feature-card {
  text-align: center;
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  background: var(--color-neon-white);
  transition: all var(--transition-normal);
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-lg);
  filter: drop-shadow(0 2px 4px rgba(220, 38, 38, 0.3));
}

.feature-title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-black);
}

.feature-description {
  color: var(--color-medium-gray);
  font-size: 1.125rem;
}

/* Datasets Section */
.datasets {
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(135deg, var(--color-light-gray) 0%, var(--color-white) 100%);
}

.datasets-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.dataset-card {
  background: var(--color-white);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  border-left: 4px solid var(--color-metallic-red);
}

.dataset-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.dataset-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.dataset-title {
  font-size: 1.5rem;
  color: var(--color-black);
  margin: 0;
}

.dataset-count {
  background: var(--color-metallic-red);
  color: var(--color-white);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: 0.875rem;
}

.dataset-description {
  color: var(--color-medium-gray);
  margin-bottom: var(--spacing-lg);
}

.dataset-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.tag {
  background: var(--color-neon-white);
  color: var(--color-black);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius);
  font-size: 0.875rem;
  font-weight: 500;
}

/* Download Section */
/* Download Section */
.download-section {
  padding: var(--spacing-3xl) 0;
  background: linear-gradient(135deg, var(--color-black) 0%, var(--color-dark-gray) 100%);
  color: var(--color-white);
  text-align: center;
}

.download-content {
  max-width: 1200px;
  margin: 0 auto;
}

.download-section .section-title {
  color: var(--color-white);
  margin-bottom: var(--spacing-xl);
}

.download-description {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-2xl);
  color: rgba(255, 255, 255, 0.8);
}

.download-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
  max-width: 1000px;
  margin-left: auto;
  margin-right: auto;
}

.download-option {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 16px;
  padding: 2rem;
  border: 1px solid rgba(255, 255, 255, 0.2);
  position: relative;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.download-option:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.download-option.premium {
  background: linear-gradient(135deg, rgba(255, 215, 0, 0.2) 0%, rgba(255, 165, 0, 0.2) 100%);
  border: 2px solid rgba(255, 215, 0, 0.4);
}

.premium-badge {
  position: absolute;
  top: -10px;
  right: 20px;
  background: linear-gradient(135deg, #ffd700 0%, #ffa500 100%);
  color: #333;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.download-option-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: white;
}

.download-option-description {
  font-size: 1rem;
  margin-bottom: 1.5rem;
  opacity: 0.9;
  line-height: 1.6;
}

.download-features {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 1rem;
  text-align: left;
}

.download-features .feature {
  font-size: 0.875rem;
  opacity: 0.9;
  padding: 0.25rem 0;
}

.download-features .feature::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 4px;
  background: #4ade80;
  border-radius: 50%;
  margin-right: 0.5rem;
}

.download-icon {
  font-size: 1.5em;
}

.download-info {
  margin-top: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.6);
}

/* Footer */
.footer {
  background: var(--color-black);
  color: var(--color-white);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

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

.footer-brand {
  max-width: 400px;
}

.footer-title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, var(--color-white), var(--color-neon-white));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-subtitle {
  color: rgba(255, 255, 255, 0.7);
  font-size: 1rem;
}

.footer-links {
  display: flex;
  gap: var(--spacing-2xl);
}

.footer-section-title {
  color: var(--color-metallic-red);
  margin-bottom: var(--spacing-md);
  font-size: 1rem;
  font-weight: 600;
}

.footer-link {
  color: rgba(255, 255, 255, 0.8);
  display: block;
  margin-bottom: var(--spacing-sm);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.6);
}

/* Loading Overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  backdrop-filter: blur(5px);
}

.loading-overlay.active {
  display: flex;
}

.loading-content {
  text-align: center;
  color: var(--color-white);
}

.loading-spinner {
  width: 60px;
  height: 60px;
  border: 4px solid rgba(255, 255, 255, 0.2);
  border-left: 4px solid var(--color-metallic-red);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--spacing-lg);
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.loading-text {
  font-size: 1.125rem;
  margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
  :root {
    --spacing-lg: 1rem;
    --spacing-xl: 1.25rem;
    --spacing-2xl: 2rem;
    --spacing-3xl: 2.5rem;
  }
  
  .hero-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-2xl);
    text-align: center;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .nav-links {
    display: none;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .footer-links {
    justify-content: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .datasets-grid,
  .features-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.875rem;
  }
  
  .btn-large {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
  }
  
  .code-preview {
    max-width: 300px;
  }
  
  .dataset-card {
    padding: var(--spacing-lg);
  }
  
  .feature-card {
    padding: var(--spacing-lg);
  }
}