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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: #333;
  background: #f9f9f9;
}

/* Hero Section — Image en fond toujours visible */
.hero {
  position: relative;
  height: 100vh;
  background: url('saxrealbook.jpeg') center center;
  background-size: cover;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: white;
  /* Assure que l’image reste visible même en mode sombre ou sur mobile */
  background-attachment: fixed;
}

.overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.content {
  z-index: 2;
  padding: 2rem;
  max-width: 800px;
}

.content h1 {
  font-size: 3.5rem;
  margin-bottom: 0.5rem;
  font-weight: 700;
  text-shadow: 2px 2px 4px rgba(0,0,0,1);
}

.content p {
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  font-weight: 300;
}

.btn {
  display: block;
    margin: 1.5rem;
  padding: 0.75rem 1.5rem;
  background: #fff;
  color: #333;
  text-decoration: none;
  border-radius: 30px;
  font-weight: 500;
  transition: all 0.3s ease;
}

.btn:hover {
  background: #f0f0f0;
  transform: translateY(-2px);
}

/* Sections */
section {
  padding: 4rem 2rem;
    background: rgba(0, 0, 0, 0.1);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
    text-align: left;
}

section h2 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  text-align: center;
  color: white;
}

/* About */
.about p {
  margin-bottom: 1rem;
  font-size: 1.1rem;
}

/* Groupes */
.groupe-card {
  background: white;
    color: #2c3e50;
    text-align: left;
  padding: 1.5rem;
  margin: 1rem 0;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,1);
}

.groupe-card h3 {
  margin-bottom: 0.5rem;
  color: #2c3e50;
}



/* Footer */
footer {
  background: #2c3e50;
  color: white;
  text-align: center;
  padding: 1.5rem 2rem;
}

footer a {
  color: #ddd;
  text-decoration: none;
  margin: 0 0.5rem;
}

footer a:hover {
  text-decoration: underline;
}

/* Bouton retour en haut */
.back-to-top {
    position: fixed;
    right: 2rem;
    bottom: 2rem;
    width: 50px;
    height: 50px;
    background: rgba(44, 62, 80, 0.9);
    color: white;
    text-decoration: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top:hover {
    background: rgba(44, 62, 80, 1);
    transform: translateY(-5px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

/* Responsive */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }
  .content p {
    font-size: 1rem;
  }
  section {
    padding: 2rem 1rem;
  }
  .container {
    padding: 0;
  }
    .back-to-top {
        right: 1rem;
        bottom: 1rem;
        width: 45px;
        height: 45px;
        font-size: 1.3rem;
    }
}