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

        /* Animation au chargement */
        @keyframes slideDown {
            from {
                transform: translateY(-100%);
                opacity: 0;
            }
            to {
                transform: translateY(0);
                opacity: 1;
            }
        }

        /* Positionnement du contenu principal */
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            padding-top: 80px; /* Espace pour le menu fixe */
            animation: slideDown 0.8s ease-out;
        }

        .main-content {
            margin-top: 30px; /* Grille positionnée 30px en dessous */
            padding: 20px;
        }

        /* Styles du header */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            box-shadow: 0 2px 15px rgba(0,0,0,0.1);
            z-index: 1000;
            height: 70px;
            animation: slideDown 0.6s ease-out;
        }

        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
            max-width: 1600px;/*   max-width: 1200px; ma page 1600px même largeur*/
            margin: 0 auto;
            padding: 0 20px;
            height: 100%;
        }

        /* Logo */
        .logo {
            font-size: 1.5rem;
            font-weight: bold;
            color: white;
            text-decoration: none;
            transition: transform 0.3s ease;
        }

        .logo:hover {
            transform: scale(1.05);
        }

        /* Menu principal desktop */
        .nav-menu {
            display: flex;
            list-style: none;
            align-items: center;
        }

        .nav-item {
            position: relative;
            margin: 0 10px;
        }

        .nav-link {
            color: white;
            text-decoration: none;
            padding: 15px 20px;
            display: block;
            transition: all 0.3s ease;
            border-radius: 5px;
            position: relative;
            overflow: hidden;
        }

        .nav-link::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: rgba(255,255,255,0.1);
            transition: left 0.3s ease;
        }

        .nav-link:hover::before {
            left: 0;
        }

        .nav-link:hover {
            background: rgba(255,255,255,0.1);
            transform: translateY(-2px);
        }

        /* Indicateur de dropdown */
        .has-dropdown > .nav-link::after {
            content: '▼';
            margin-left: 8px;
            font-size: 0.8rem;
            transition: transform 0.3s ease;
        }

        .has-dropdown:hover > .nav-link::after {
            transform: rotate(180deg);
        }

        /* Dropdowns */
        .dropdown {
            position: absolute;
            top: 100%;
            left: 0;
            background: white;
            min-width: 200px;
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            border-radius: 8px;
            opacity: 0;
            visibility: hidden;
            transform: translateY(-10px);
            transition: all 0.3s ease;
            z-index: 1001;
        }

        .nav-item:hover .dropdown {
            opacity: 1;
            visibility: visible;
            transform: translateY(0);
        }

        .dropdown-item {
            position: relative;
        }

        .dropdown-link {
            color: #333;
            padding: 12px 20px;
            display: block;
            text-decoration: none;
            transition: all 0.3s ease;
            border-bottom: 1px solid #f0f0f0;
        }

        .dropdown-link:hover {
            background: #f8f9fa;
            padding-left: 30px;
            color: #667eea;
        }

        /* Dropdown niveau 2 */
        .dropdown-item.has-submenu > .dropdown-link::after {
            content: '▶';
            position: absolute;
            right: 15px;
            top: 50%;
            transform: translateY(-50%);
            font-size: 0.8rem;
        }

        .submenu {
            position: absolute;
            top: 0;
            left: 100%;
            background: white;
            min-width: 180px;
            box-shadow: 0 8px 25px rgba(0,0,0,0.15);
            border-radius: 8px;
            opacity: 0;
            visibility: hidden;
            transform: translateX(-10px);
            transition: all 0.3s ease;
        }

        .dropdown-item:hover .submenu {
            opacity: 1;
            visibility: visible;
            transform: translateX(0);
        }

        /* Menu hamburger */
        .hamburger {
            display: none;
            flex-direction: column;
            cursor: pointer;
            padding: 10px;
            z-index: 1002;
        }

        .hamburger span {
            width: 25px;
            height: 3px;
            background: white;
            margin: 3px 0;
            transition: 0.3s;
            border-radius: 2px;
        }

        /* Checkbox caché pour gérer l'état du menu */
        .menu-toggle {
            display: none;
        }

        /* Animation hamburger */
        .menu-toggle:checked ~ .hamburger span:nth-child(1) {
            transform: rotate(-45deg) translate(-6px, 6px);
        }

        .menu-toggle:checked ~ .hamburger span:nth-child(2) {
            opacity: 0;
        }

        .menu-toggle:checked ~ .hamburger span:nth-child(3) {
            transform: rotate(45deg) translate(-6px, -6px);
        }

        /* Menu mobile */
        .mobile-menu {
            position: fixed;
            top: 70px;
            right: -100%;
            width: 300px;
            height: calc(100vh - 70px);
            background: white;
            box-shadow: -5px 0 15px rgba(0,0,0,0.1);
            transition: right 0.4s ease;
            overflow-y: auto;
            z-index: 999;
        }

        /* Variantes de position du menu mobile */
        .mobile-menu.position-left {
            left: -100%;
            right: auto;
            box-shadow: 5px 0 15px rgba(0,0,0,0.1);
            transition: left 0.4s ease;
        }

        .mobile-menu.position-top {
            top: 70px;
            left: 0;
            right: 0;
            width: 100%;
            height: 0;
            transition: height 0.4s ease;
        }

        .mobile-menu.position-bottom {
            bottom: 0;
            top: auto;
            left: 0;
            right: 0;
            width: 100%;
            height: 0;
            transition: height 0.4s ease;
        }

        .menu-toggle:checked ~ .mobile-menu {
            right: 0;
        }

        .menu-toggle:checked ~ .mobile-menu.position-left {
            left: 0;
        }

        .menu-toggle:checked ~ .mobile-menu.position-top,
        .menu-toggle:checked ~ .mobile-menu.position-bottom {
            height: calc(100vh - 70px);
        }

        /* Styles des liens mobiles */
        .mobile-nav-item {
            border-bottom: 1px solid #f0f0f0;
        }

        .mobile-nav-link {
            color: #333;
            text-decoration: none;
            padding: 15px 20px;
            display: block;
            transition: all 0.3s ease;
        }

        .mobile-nav-link:hover {
            background: #f8f9fa;
            padding-left: 30px;
            color: #667eea;
        }

        /* Dropdown mobile */
        .mobile-dropdown-toggle {
            display: none;
        }

        .mobile-has-dropdown > .mobile-nav-link::after {
            content: '▼';
            float: right;
            transition: transform 0.3s ease;
        }

        .mobile-dropdown-toggle:checked ~ .mobile-nav-link::after {
            transform: rotate(180deg);
        }

        .mobile-dropdown {
            max-height: 0;
            overflow: hidden;
            background: #f8f9fa;
            transition: max-height 0.3s ease;
        }

        .mobile-dropdown-toggle:checked ~ .mobile-dropdown {
            max-height: 500px;
        }

        .mobile-dropdown-link {
            color: #666;
            padding: 10px 40px;
            display: block;
            text-decoration: none;
            transition: all 0.3s ease;
            border-bottom: 1px solid #e9ecef;
        }

        .mobile-dropdown-link:hover {
            background: white;
            color: #667eea;
            padding-left: 50px;
        }

        /* Overlay pour fermer le menu */
        .menu-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.5);
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
            z-index: 998;
        }

        .menu-toggle:checked ~ .menu-overlay {
            opacity: 1;
            visibility: visible;
        }

        /* Media queries pour responsive */
        @media (max-width: 768px) {
            .nav-menu {
                display: none;
            }

            .hamburger {
                display: flex;
            }

            body {
                padding-top: 70px;
            }
        }

        @media (max-width: 480px) {
            .mobile-menu {
                width: 100%;
            }

            .nav-container {
                padding: 0 15px;
            }
        }

        /* Contenu de démonstration */
        .demo-content {
            padding: 40px 20px;
            max-width: 1200px;
            margin: 0 auto;
        }

        .demo-section {
            background: white;
            padding: 30px;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            margin-bottom: 30px;
        }

        .demo-section h2 {
            color: #667eea;
            margin-bottom: 15px;
        }