.header {
  background-color: var(--bg-primary);
  box-shadow: 0 2px 4px var(--shadow-color);
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
}

.header nav {
  display: flex;
  justify-content: center;
  gap: 2rem;
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
}

.nav-link {
  font-weight: 500;
  color: var(--text-primary);
  transition: color var(--transition-speed);
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--text-primary);
  transition: width var(--transition-speed);
}

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

/* Style pour le conteneur du bouton de thème */
.theme-toggle-container {
  margin-left: auto;
  padding-left: 2rem;
}