/* --- LE HEADER --- */
header {
    width: 100%;
    background-color: rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    padding: 15px 20px;
    position: sticky;
    top: 0;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    transition: background-color 0.3s ease;
}

header:hover { background-color: rgba(255, 255, 255, 0.6); }

.brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: #2c3e50;
    text-decoration: none;
    letter-spacing: 2px;
}

nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.nav-link {
    text-decoration: none;
    color: #444;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.95rem;
    font-weight: 600;
    background-color: rgba(255,255,255,0.4);
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

/* Effet Halo lumineux */
.nav-link::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: radial-gradient(circle 40px at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(255, 255, 255, 0.8), transparent 100%);
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
    z-index: 1;
    mix-blend-mode: overlay;
}

.nav-link:hover::before {
    opacity: 1;
}

/* Application du style pour le survol et l'onglet actif */
.nav-link.active,
.nav-link:hover {
    background-color: #007bff;
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,123,255,0.3);
}

/* --- MOBILE HEADER --- */
@media (max-width: 600px) {
    header { padding: 10px; }
    .brand { font-size: 1.2rem; }
    .nav-link { font-size: 0.85rem; padding: 6px 12px; }
}