/* ==================== VARIABLES ==================== */
:root {
  --primary: #635BFF;
  --primary-dark: #4F46E5;
  --primary-light: #818CF8;
  --secondary: #1E293B;
  --accent: #06B6D4;
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;
  --gray-50: #F8FAFC;
  --gray-100: #F1F5F9;
  --gray-200: #E2E8F0;
  --gray-300: #CBD5E1;
  --gray-400: #94A3B8;
  --gray-500: #64748B;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1E293B;
  --gray-900: #0F172A;
  --white: #FFFFFF;
  --gradient-primary: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --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);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  --radius-sm: 0.375rem;
  --radius: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
}

/* ==================== RESET & BASE ==================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-700);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

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

/* ==================== TYPOGRAPHY ==================== */
h1, h2, h3, h4, h5, h6 {
  color: var(--gray-900);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: 1rem;
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ==================== LAYOUT ==================== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 4rem;
}

.section-header p {
  font-size: 1.125rem;
  color: var(--gray-500);
}

/* ==================== BUTTONS ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-lg);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--white);
}

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

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

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

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

/* ==================== NAVBAR ==================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-200);
  transition: all 0.3s ease;
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
}

.navbar-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.navbar-logo {
  display: flex;
  align-items: center;
}

.navbar-logo img {
  height: 40px;
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.navbar-menu a {
  color: var(--gray-600);
  font-weight: 500;
  transition: color 0.2s ease;
}

.navbar-menu a:hover {
  color: var(--primary);
}

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

.lang-switch {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem;
  border-radius: var(--radius);
  background: var(--gray-100);
}

.lang-switch a {
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--gray-500);
}

.lang-switch a.active {
  background: var(--white);
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

/* ==================== HERO ==================== */
.hero {
  padding: 8rem 0 5rem;
  background: linear-gradient(180deg, var(--gray-50) 0%, var(--white) 100%);
  overflow: hidden;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-content h1 {
  margin-bottom: 1.5rem;
}

.hero-content p {
  font-size: 1.25rem;
  color: var(--gray-500);
  margin-bottom: 2rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.github-stars-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.4rem 0.75rem;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: 2rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--gray-700);
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.github-stars-badge:hover {
  color: var(--gray-900);
  border-color: var(--warning);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.github-stars-badge .star-icon {
  color: var(--warning);
  font-size: 1.125rem;
}

.hero-image {
  position: relative;
}

.hero-image img {
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
}

.hero-badge {
  position: absolute;
  background: var(--white);
  padding: 1rem 1.5rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.hero-badge.top-left {
  top: -1rem;
  left: -1rem;
}

.hero-badge.bottom-right {
  bottom: 2rem;
  right: -1rem;
}

.hero-badge-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.hero-badge-icon.success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.hero-badge-icon.danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }

.hero-badge-text {
  font-size: 0.875rem;
}

.hero-badge-text strong {
  display: block;
  font-size: 1rem;
  color: var(--gray-900);
}

/* ==================== FEATURES ==================== */
.features {
  background: var(--white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  padding: 2rem;
  border-radius: var(--radius-xl);
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
  transition: all 0.3s ease;
}

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

.feature-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: var(--gray-500);
  margin-bottom: 0;
}

/* ==================== HOW IT WORKS ==================== */
.how-it-works {
  background: var(--gray-50);
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  position: relative;
}

.steps::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 10%;
  right: 10%;
  height: 2px;
  background: var(--gray-200);
  z-index: 0;
}

.step {
  text-align: center;
  position: relative;
  z-index: 1;
}

.step-number {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--primary);
  color: var(--primary);
  font-size: 2rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
}

.step h4 {
  margin-bottom: 0.5rem;
}

.step p {
  color: var(--gray-500);
  font-size: 0.9375rem;
}

/* ==================== PLATFORM PREVIEW ==================== */
.platform-preview {
  background: var(--gray-50);
}

.preview-items {
  display: flex;
  flex-direction: column;
  gap: 4rem;
}

.preview-item {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 3rem;
  align-items: center;
}

.preview-item.reverse {
  grid-template-columns: 1.2fr 1fr;
}

.preview-item.reverse .preview-text {
  order: 2;
}

.preview-item.reverse .preview-image {
  order: 1;
}

.preview-text h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.preview-text p {
  color: var(--gray-500);
  font-size: 1.0625rem;
  line-height: 1.7;
  margin-bottom: 0;
}

.preview-image img {
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--gray-200);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.preview-image img:hover {
  transform: scale(1.02);
  box-shadow: 0 25px 50px -12px rgb(0 0 0 / 0.15);
}

@media (max-width: 1024px) {
  .preview-item,
  .preview-item.reverse {
    grid-template-columns: 1fr;
  }

  .preview-item.reverse .preview-text,
  .preview-item.reverse .preview-image {
    order: unset;
  }
}

/* ==================== USE CASES ==================== */
.use-cases {
  background: var(--white);
}

.use-cases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.use-case-card {
  display: flex;
  gap: 1.5rem;
  padding: 2rem;
  border-radius: var(--radius-xl);
  background: var(--gray-50);
  border: 1px solid var(--gray-200);
}

.use-case-icon {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.use-case-content h4 {
  margin-bottom: 0.5rem;
}

.use-case-content p {
  color: var(--gray-500);
  margin-bottom: 0;
}

/* ==================== CTA ==================== */
.cta {
  background: var(--gradient-primary);
  color: var(--white);
  text-align: center;
}

.cta h2 {
  color: var(--white);
}

.cta p {
  font-size: 1.25rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 2rem;
}

.cta-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ==================== FOOTER ==================== */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  margin-top: 1rem;
  font-size: 0.9375rem;
}

.footer-title {
  color: var(--white);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: var(--gray-400);
  font-size: 0.9375rem;
}

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

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--gray-800);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
}

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social a {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--gray-800);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gray-400);
  transition: all 0.2s ease;
}

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

/* ==================== RESPONSIVE ==================== */
@media (max-width: 1024px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    display: none;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps::before {
    display: none;
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .navbar-menu {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .section {
    padding: 3rem 0;
  }

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

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

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

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

/* ==================== ANIMATIONS ==================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fadeInUp {
  animation: fadeInUp 0.6s ease forwards;
}

.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }