/* header.css : styles pour l'en-tête du site */

header {
  background: linear-gradient(120deg, #232946 0%, #3a4be7 60%, #6c63ff 100%);
  color: #fff;
  padding: 2.5rem 1rem 2rem 1rem;
  text-align: center;
  box-shadow: 0 8px 32px 0 rgba(35,41,70,0.18), 0 1.5px 0 #fff2 inset;
  border-bottom-left-radius: 32px;
  border-bottom-right-radius: 32px;
  position: relative;
  z-index: 2;
  overflow: hidden;
}
header::before {
  content: '';
  position: absolute;
  top: -40px; left: 50%;
  width: 400px; height: 120px;
  background: radial-gradient(circle, #b8c1ec55 0%, transparent 80%);
  transform: translateX(-50%);
  z-index: 1;
  pointer-events: none;
}
header h1 {
  margin: 0.2em 0 0.1em 0;
  font-size: 2.7rem;
  letter-spacing: 1px;
  font-weight: 800;
  text-shadow: 0 4px 24px #6c63ff55, 0 1px 0 #fff2;
  position: relative;
  z-index: 2;
}
.subtitle {
  font-size: 1.2rem;
  color: #b8c1ec;
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 2;
}
nav {
  margin-top: 1.2rem;
  position: relative;
  z-index: 2;
}
nav a {
  color: #fff;
  background: rgba(0,102,204,0.85);
  padding: 0.5em 1.2em;
  border-radius: 24px;
  margin: 0 8px;
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s, transform 0.2s;
  box-shadow: 0 2px 12px 0 #0066cc33, 0 1.5px 0 #fff2 inset;
  display: inline-block;
  border: none;
  position: relative;
}
nav a:hover {
  background: #b8c1ec;
  color: #232946;
  box-shadow: 0 8px 32px #0066cc55, 0 1.5px 0 #fff2 inset;
  transform: translateY(-3px) scale(1.05);
  filter: brightness(1.1);
}
.header-flex {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.2rem;
}
.header-socials {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
}
.main-nav {
  margin-top: 1.2rem;
  position: relative;
  z-index: 2;
}
.main-nav a {
  color: #fff;
  background: rgba(0,102,204,0.85);
  padding: 0.5em 1.2em;
  border-radius: 24px;
  margin: 0 8px;
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s, transform 0.2s;
  box-shadow: 0 2px 12px 0 #0066cc33, 0 1.5px 0 #fff2 inset;
  display: inline-block;
  border: none;
  position: relative;
}
.main-nav a:hover {
  background: #b8c1ec;
  color: #232946;
  box-shadow: 0 8px 32px #0066cc55, 0 1.5px 0 #fff2 inset;
  transform: translateY(-3px) scale(1.05);
  filter: brightness(1.1);
}
@media (max-width: 600px) {
  header h1 { font-size: 1.3rem; }
  .subtitle { font-size: 1rem; }
  nav a { font-size: 0.98em; padding: 0.4em 0.7em; }
}