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

:root {
  /* Colors */
  --bg-main: #0F172A;
  --bg-deep: #070B18;
  --surface: #111827;
  --surface-light: #171f33;
  --primary-blue: #38BDF8;
  --primary-blue-glow: rgba(56, 189, 248, 0.5);
  --accent-purple: #A855F7;
  --accent-purple-glow: rgba(168, 85, 247, 0.5);
  --accent-gold: #F5C542;
  --text-main: #dae2fd;
  --text-secondary: #94A3B8;
  --border-color: rgba(255, 255, 255, 0.12);

  /* Glassmorphism */
  --glass-bg: rgba(17, 24, 39, 0.6);
  --glass-blur: blur(12px);

  /* Radius & Spacing */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --container-width: 1200px;
  --section-padding: 80px 20px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-main);
  background-image: radial-gradient(circle at 15% 10%, rgba(56, 189, 248, 0.1), transparent 40%),
                    radial-gradient(circle at 85% 60%, rgba(168, 85, 247, 0.1), transparent 40%);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

a:focus-visible, button:focus-visible {
  outline: 2px solid var(--primary-blue);
  outline-offset: 4px;
}

ul {
  list-style: none;
}

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

/* Typography */
h1, h2, h3, h4 {
  color: #ffffff;
  line-height: 1.2;
  margin-bottom: 16px;
}

h1 {
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

p {
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: 24px;
}

/* Layout Utilities */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

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

.section {
  padding: var(--section-padding);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-blue), var(--accent-purple));
  color: #fff;
  box-shadow: 0 4px 20px var(--primary-blue-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(168, 85, 247, 0.6);
  color: #fff;
}

.btn-secondary {
  background: var(--surface-light);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--surface);
  border-color: var(--primary-blue);
  transform: translateY(-2px);
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border-color);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo img {
  height: 32px;
}

.nav-links {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nav-links a {
  font-weight: 500;
  font-size: 0.95rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 24px;
}

.lang-selector {
  background: transparent;
  color: var(--text-secondary);
  border: none;
  font-size: 0.9rem;
  cursor: pointer;
}

.lang-selector:focus {
  outline: none;
}

/* Hero Section */
.hero {
  padding-top: 160px;
  padding-bottom: 100px;
  min-height: 90vh;
  display: flex;
  align-items: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-content h1 {
  background: linear-gradient(to right, #fff, var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-ctas {
  display: flex;
  gap: 16px;
  margin-top: 32px;
}

.hero-visual {
  position: relative;
  height: 500px;
}

.floating-card {
  position: absolute;
  background: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  backdrop-filter: var(--glass-blur);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  animation: float 6s ease-in-out infinite;
}

.card-1 {
  top: 20%;
  left: 10%;
  width: 220px;
  height: 300px;
  background: linear-gradient(145deg, var(--surface), var(--surface-light));
  animation-delay: 0s;
}

.card-1::before {
  content: '';
  position: absolute;
  top: 16px; left: 16px; right: 16px; bottom: 80px;
  background: rgba(255,255,255,0.05);
  border-radius: var(--radius-sm);
}

.card-2 {
  top: 40%;
  right: 10%;
  width: 200px;
  height: 260px;
  background: linear-gradient(145deg, var(--surface-light), var(--surface));
  animation-delay: -3s;
  border-color: rgba(168, 85, 247, 0.3);
}

.card-3 {
  bottom: 10%;
  left: 30%;
  width: 180px;
  height: 220px;
  background: linear-gradient(145deg, var(--surface), var(--surface-light));
  animation-delay: -1.5s;
  border-color: rgba(56, 189, 248, 0.3);
}

@keyframes float {
  0% { transform: translateY(0px) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(2deg); }
  100% { transform: translateY(0px) rotate(0deg); }
}

/* Features - O App */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 60px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-blue);
  background: linear-gradient(180deg, var(--surface), var(--surface-light));
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(56, 189, 248, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--primary-blue);
}

/* Community Section */
.community {
  background: var(--bg-deep);
  position: relative;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.community-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.community-visual {
  position: relative;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.node {
  position: absolute;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--surface-light);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 20px var(--primary-blue-glow);
}

.node-center {
  width: 96px;
  height: 96px;
  z-index: 2;
  border-color: var(--accent-purple);
  box-shadow: 0 0 30px var(--accent-purple-glow);
}

.node-1 { top: 20%; left: 20%; }
.node-2 { top: 15%; right: 25%; }
.node-3 { bottom: 25%; left: 15%; }
.node-4 { bottom: 20%; right: 20%; }

.connection-line {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 200px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--primary-blue), transparent);
  transform-origin: left center;
  opacity: 0.5;
}

/* Showcase Central */
.showcase {
  text-align: center;
}

.showcase-container {
  margin-top: 60px;
  background: var(--surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: 0 30px 60px rgba(0,0,0,0.5);
}

.dashboard-abstract {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 24px;
  height: 400px;
}

.dash-sidebar {
  background: var(--surface-light);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.dash-item {
  height: 32px;
  background: rgba(255,255,255,0.05);
  border-radius: var(--radius-sm);
}

.dash-main {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: 120px 1fr;
  gap: 24px;
}

.dash-stat {
  background: var(--surface-light);
  border-radius: var(--radius-md);
  padding: 24px;
  border-left: 2px solid var(--primary-blue);
}

.dash-content {
  grid-column: 1 / -1;
  background: var(--surface-light);
  border-radius: var(--radius-md);
}

/* CTA Download */
.cta-download {
  text-align: center;
  background: linear-gradient(180deg, var(--bg-main), var(--bg-deep));
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 40px;
}

/* Privacy Section snippet */
.privacy-teaser {
  background: var(--bg-deep);
  text-align: center;
  border-top: 1px solid var(--border-color);
}

/* Institutional Pages (Privacy, Terms, Support) */
.page-header {
  padding-top: 160px;
  padding-bottom: 60px;
  background: var(--bg-deep);
  border-bottom: 1px solid var(--border-color);
}

.content-section {
  padding: 60px 0;
  max-width: 800px;
  margin: 0 auto;
}

.content-section h2 {
  margin-top: 48px;
  font-size: 1.75rem;
}

.content-section p, .content-section li {
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: 16px;
}

.content-section ul {
  list-style: disc;
  margin-left: 24px;
  margin-bottom: 24px;
}

/* Footer */
.footer {
  background: var(--bg-deep);
  padding: 80px 0 40px;
  border-top: 1px solid var(--border-color);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 60px;
}

.footer-logo img {
  height: 32px;
  margin-bottom: 24px;
}

.footer-links h4 {
  font-size: 1.125rem;
  margin-bottom: 24px;
  color: #fff;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 32px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 960px) {
  h1 { font-size: 3rem; }
  h2 { font-size: 2.25rem; }
  
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-ctas {
    justify-content: center;
  }
  
  .hero-visual {
    height: 400px;
  }
  
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .community-grid {
    grid-template-columns: 1fr;
  }
  
  .community-grid .community-content {
    order: -1;
    text-align: center;
  }
  
  .dashboard-abstract {
    grid-template-columns: 1fr;
    height: auto;
  }
  
  .dash-sidebar {
    flex-direction: row;
    overflow-x: auto;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 720px) {
  .nav-links {
    display: none; /* Mobile menu hidden for simplicity in prototype */
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .dash-main {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }
  
  .download-buttons {
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  h1 { font-size: 2.5rem; }
  .section { padding: 60px 20px; }
  .footer-grid { grid-template-columns: 1fr; }
}