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

:root {
  --primary: #0B0F2B;
  --secondary: #1F6FFF;
  --accent: #4A90E2;
  --light: #F5F5F5;
  --text: #FFFFFF;
  --text-light: #E0E0E0;
  --text-dark: #333333;
  --border: rgba(31, 111, 255, 0.2);
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--primary);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3 {
  font-weight: 600;
  line-height: 1.3;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--secondary);
}

h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
  color: var(--secondary);
}

h3 {
  font-size: 1.2rem;
  margin: 0.8rem 0;
  color: var(--text);
}

p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  color: var(--text-light);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 50px;
}

/* Animated background video */
.background-video {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  opacity: 0.2;
}

.background-video video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(11, 15, 43, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  border-bottom: 1px solid var(--border);
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 50px;
}

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

.back-button {
  font-size: 1.5rem;
  color: var(--secondary);
  text-decoration: none;
  transition: color 0.3s ease;
}

.back-button:hover {
  color: var(--accent);
}

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

.nav {
  display: flex;
  gap: 2rem;
}

.nav-link {
  color: white;
  text-decoration: none;
  font-size: 1rem;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--secondary);
}

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

/* Sections */
.section {
  padding: 80px 0;
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.bg-dark {
  background: var(--primary);
}

.bg-light {
  background: var(--light);
  color: var(--text-dark);
}

.bg-light h1, .bg-light h2, .bg-light h3, .bg-light p {
  color: var(--text-dark);
}

/* Hero */
.hero-container {
  display: flex;
  align-items: center;
  gap: 4rem;
}

.hero-content {
  flex: 1;
}

.hero-title {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  color: var(--secondary);
}

.hero-subtitle {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  color: var(--accent);
}

.hero-text {
  font-size: 1.1rem;
  margin-bottom: 2rem;
  color: var(--text-light);
}

.hero-visual {
  flex: 1;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.neural-circle {
  position: absolute;
  width: 300px;
  height: 300px;
  border: 2px solid var(--secondary);
  border-radius: 50%;
  opacity: 0.3;
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.3; }
  50% { transform: scale(1.1); opacity: 0.6; }
}

.illustration {
  width: 300px;
  height: 200px;
  border-radius: 15px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border);
}

.illustration-small {
  width: 250px;
  height: 180px;
  border-radius: 12px;
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

/* Animations pour les images */
.brain-ai {
  animation: pulse 3s ease-in-out infinite;
}

.ai-silhouette {
  animation: pulse-silhouette 3s ease-in-out infinite;
}

@keyframes pulse-silhouette {
  0%, 100% { transform: scale(1); opacity: 0.8; }
  50% { transform: scale(1.05); opacity: 1; }
}

.stylized-hand {
  animation: pulse-glow 2.5s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% {
    box-shadow: 0 0 15px rgba(31, 111, 255, 0.3);
    transform: scale(1);
  }
  50% {
    box-shadow: 0 0 25px rgba(31, 111, 255, 0.7);
    transform: scale(1.03);
  }
}

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.feature-card {
  background: rgba(31, 111, 255, 0.1);
  padding: 2rem;
  border-radius: 12px;
  text-align: center;
  border: 1px solid var(--border);
  transition: all 0.3s ease;
}

.feature-card:hover {
  background: rgba(31, 111, 255, 0.2);
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 1rem;
}

/* À propos */
.about-container {
  display: flex;
  align-items: center;
  gap: 4rem;
}

.about-content {
  flex: 1;
}

.about-visual {
  flex: 1;
  display: flex;
  justify-content: center;
}

/* Contact */
.contact-container {
  display: flex;
  gap: 4rem;
  align-items: flex-start;
}

.contact-content {
  flex: 1;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 500px;
}

.contact-form input,
.contact-form textarea {
  padding: 1rem;
  border: 1px solid #ddd;
  border-radius: 8px;
  font-family: inherit;
  font-size: 1rem;
}

.btn {
  background: var(--secondary);
  color: white;
  border: none;
  padding: 1rem 2rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  align-self: flex-start;
  transition: all 0.3s ease;
}

.btn:hover {
  background: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(31, 111, 255, 0.3);
}

/* Footer */
.footer {
  background: var(--primary);
  color: white;
  padding: 2rem 0;
  border-top: 1px solid var(--border);
}

.footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 50px;
}

.footer-brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--secondary);
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-link {
  color: white !important;
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease;
  position: relative;
  padding-bottom: 2px;
}

.footer-link:visited {
  color: white !important;
}

.footer-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--secondary);
  transition: width 0.3s ease;
}

.footer-link:hover {
  color: var(--secondary) !important;
}

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

/* Responsive */
@media (max-width: 768px) {
  .container,
  .header .container,
  .footer .container {
    padding: 0 20px;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  p { font-size: 1rem; }
  
  .hero-container,
  .about-container,
  .contact-container {
    flex-direction: column;
    text-align: center;
  }
  
  .hero-visual,
  .about-visual,
  .contact-visual {
    margin-top: 2rem;
  }
  
  .illustration {
    width: 100%;
    max-width: 250px;
    height: 150px;
  }
  
  .illustration-small {
    max-width: 200px;
    height: 130px;
  }
  
  .nav {
    flex-direction: column;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    order: 2;
    width: 100%;
  }

  .nav.active {
    max-height: 300px;
  }

  .nav-link {
    padding: 0.8rem 0;
    display: flex;
    justify-content: flex-start;
  }

  .header-left {
    order: 1;
    width: 100%;
    justify-content: space-between;
  }
}

/* Garantie 100% responsive */
html, body {
  width: 100%;
  overflow-x: hidden;
}