/* ============================================
   VTech-Hub — Linear-inspired Design System
   Dark, Precise, Indigo-Accented
   ============================================ */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

/* === CSS Variables — Theme Tokens === */
:root {
  /* Backgrounds */
  --bg-deep: #08090a;
  --bg-page: #0f1011;
  --bg-surface: #191a1b;
  --bg-elevated: #23252a;
  
  /* Text */
  --text-primary: #f7f8f8;
  --text-secondary: #8a8f98;
  --text-muted: #62666d;
  
  /* Brand — Indigo */
  --brand: #5e6ad2;
  --brand-light: #7170ff;
  --brand-hover: #828fff;
  
  /* Status */
  --success: #27a644;
  --success-bg: rgba(39, 166, 68, 0.1);
  --error: #cf2d56;
  
  /* Borders */
  --border-default: rgba(255, 255, 255, 0.08);
  --border-subtle: rgba(255, 255, 255, 0.05);
  
  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, monospace;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  
  /* Radius */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-secondary);
  line-height: 1.6;
  min-height: 100vh;
  font-feature-settings: 'cv01', 'ss03';
}

/* === Typography === */
h1, h2, h3, h4 {
  color: var(--text-primary);
  font-weight: 510;
}

h1 {
  font-size: clamp(2rem, 5vw, 48px);
  line-height: 1.00;
  letter-spacing: -1.056px;
  margin-bottom: var(--space-6);
}

h2 {
  font-size: clamp(1.5rem, 3vw, 32px);
  line-height: 1.13;
  letter-spacing: -0.704px;
  margin-bottom: var(--space-4);
}

h3 {
  font-size: 20px;
  line-height: 1.33;
  letter-spacing: -0.24px;
  margin-bottom: var(--space-2);
}

p {
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
}

a {
  color: var(--brand-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--brand-hover);
}

/* === Layout === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section-header p {
  font-size: 18px;
  max-width: 600px;
  margin: 0 auto;
  color: var(--text-secondary);
}

/* === Navigation === */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 16, 17, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
  padding: 0 var(--space-6);
}

.nav-logo {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text-primary);
  letter-spacing: -0.3px;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-logo:hover {
  color: var(--text-primary);
}

.nav-logo .logo-icon {
  width: 8px;
  height: 8px;
  background: var(--brand);
  border-radius: 50%;
  display: inline-block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 510;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.04);
}

.nav-cta {
  background: var(--brand);
  color: #fff !important;
  padding: 0.5rem 1rem !important;
  border-radius: var(--radius-md);
  font-weight: 510;
  font-size: 13px;
}
.nav-cta:hover {
  background: var(--brand-light) !important;
  color: #fff !important;
}

/* === Hero Section === */
.hero {
  padding: var(--space-16) 0 var(--space-12);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(94, 106, 210, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border-default);
  border-radius: 9999px;
  padding: 0.35rem 1rem;
  font-size: 13px;
  font-weight: 510;
  color: var(--text-secondary);
  margin-bottom: var(--space-8);
}

.hero p {
  font-size: 18px;
  max-width: 600px;
  margin: 0 auto var(--space-8);
  color: var(--text-secondary);
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 510;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--brand);
  color: #fff;
  border-color: var(--brand);
}
.btn-primary:hover {
  background: var(--brand-light);
  border-color: var(--brand-light);
  color: #fff;
}

.btn-secondary {
  background: rgba(255,255,255,0.04);
  color: var(--text-primary);
  border-color: var(--border-default);
}
.btn-secondary:hover {
  background: rgba(255,255,255,0.08);
  color: var(--text-primary);
}

.btn-ghost {
  background: rgba(255,255,255,0.02);
  color: var(--text-secondary);
  border-color: var(--border-subtle);
}
.btn-ghost:hover {
  background: rgba(255,255,255,0.05);
  color: var(--text-primary);
}

/* === Feature Cards === */
.feature-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.feature-card {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-base);
  text-decoration: none;
  display: block;
}

.feature-card:hover {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.12);
  transform: translateY(-1px);
}

.feature-card h3 {
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.feature-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

.feature-card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 13px;
  font-weight: 510;
  color: var(--brand-light);
  margin-top: var(--space-3);
}

/* === Section === */
.section {
  padding: var(--space-20) 0;
  border-top: 1px solid var(--border-subtle);
}

/* === Latest Articles === */
.article-list {
  max-width: 700px;
  margin: 0 auto;
}

.article-item {
  display: block;
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--border-subtle);
  text-decoration: none;
  transition: all var(--transition-fast);
}
.article-item:last-child {
  border-bottom: none;
}

.article-item:hover {
  padding-left: var(--space-2);
}

.article-item h3 {
  font-size: 16px;
  font-weight: 510;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.article-item p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* === Features Section (Was wir bieten) === */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-4);
}

.feature-box {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all var(--transition-base);
  text-decoration: none;
  display: block;
}

.feature-box:hover {
  background: rgba(255,255,255,0.04);
  transform: translateY(-1px);
}

.feature-box h3 {
  margin-bottom: var(--space-2);
}

.feature-box p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* === KI Section === */
.ki-section {
  padding: var(--space-20) 0;
}

.ki-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: center;
}

.ki-content {
  max-width: 500px;
}

.ki-card {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
}

.ki-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.ki-card-icon {
  width: 40px;
  height: 40px;
  background: rgba(94, 106, 210, 0.15);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}

.ki-card-title {
  font-weight: 510;
  color: var(--text-primary);
  font-size: 16px;
}

.ki-card-subtitle {
  font-size: 13px;
  color: var(--text-muted);
}

.ki-card-content {
  background: rgba(0, 0, 0, 0.3);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
}

.ki-features {
  list-style: none;
  margin-top: var(--space-6);
}

.ki-features li {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-2);
  font-size: 14px;
  color: var(--text-secondary);
}

.ki-features li::before {
  content: '→';
  color: var(--brand-light);
  font-family: var(--font-mono);
  font-weight: 500;
}

/* === Crypto Section === */
.crypto-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

.crypto-card {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-align: center;
  transition: all var(--transition-base);
}

.crypto-card:hover {
  background: rgba(255,255,255,0.04);
  border-color: rgba(255,255,255,0.12);
}

.crypto-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border-default);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.crypto-card h3 {
  margin-bottom: var(--space-2);
}

.crypto-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.crypto-price {
  font-size: 28px;
  font-weight: 600;
  color: var(--success);
  margin-bottom: 0.25rem;
  font-feature-settings: 'tnum';
}

.crypto-change {
  font-size: 13px;
  color: var(--success);
  font-weight: 510;
}

/* === Related Content === */
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-4);
}

.related-card {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-decoration: none;
  display: block;
  transition: all var(--transition-base);
}

.related-card:hover {
  background: rgba(255,255,255,0.04);
  transform: translateY(-1px);
}

.related-card-icon {
  font-size: 2rem;
  margin-bottom: var(--space-3);
}

.related-card h3 {
  font-size: 16px;
  margin-bottom: var(--space-1);
}

.related-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* === CTA Box === */
.cta-box {
  text-align: center;
  margin-top: var(--space-8);
  padding: var(--space-8);
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xl);
}

.cta-box h3 {
  margin-bottom: var(--space-2);
  font-size: 24px;
  letter-spacing: -0.288px;
}

.cta-box p {
  color: var(--text-muted);
  margin-bottom: var(--space-6);
}

/* === Footer === */
.footer {
  padding: var(--space-12) 0 var(--space-8);
  border-top: 1px solid var(--border-subtle);
  margin-top: 0;
}

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

.footer-brand p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.footer-heading {
  font-size: 13px;
  font-weight: 510;
  color: var(--text-primary);
  margin-bottom: var(--space-4);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  font-size: 13px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  padding-top: var(--space-6);
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-bottom p {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 0;
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-4);
}

.footer-bottom-links a {
  font-size: 12px;
  color: var(--text-muted);
  text-decoration: none;
}

.footer-bottom-links a:hover {
  color: var(--text-primary);
}

/* === Responsive === */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--bg-page);
    border-bottom: 1px solid var(--border-default);
    padding: var(--space-4);
  }
  
  .nav-toggle {
    display: block;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: var(--space-2);
  }
  
  .crypto-grid {
    grid-template-columns: 1fr;
  }
  
  .ki-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  
  .hero {
    padding: var(--space-8) 0 var(--space-6);
  }
  
  .section {
    padding: var(--space-8) 0;
  }
  
  .feature-cards {
    grid-template-columns: 1fr;
  }
  
  .feature-grid {
    grid-template-columns: 1fr;
  }
  
  .related-grid {
    grid-template-columns: 1fr 1fr;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .related-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-buttons .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
}

@media (min-width: 769px) {
  .nav-toggle {
    display: none;
  }
}