body {
            background-image: url('https://images.unsplash.com/photo-1507842217343-583bb7270b66?ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80');
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            background-repeat: no-repeat;
            position: relative;
            min-height: 100vh;
            margin: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5); /* Overlay noir semi-transparent */
            z-index: -1;
            transition: background-color 0.5s ease;
        }
        
        /* Dark Mode - Overlay plus foncé */
        body.dark::before {
            background: rgba(0, 0, 0, 0.7);
        }
        
        /* Animation d'entrée */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        /* Carte principale */
        .premium-card {
            background: rgba(255, 255, 255, 0.9); /* Fond blanc légèrement transparent */
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            overflow: hidden;
            animation: fadeIn 0.6s ease-out forwards;
        }
        
        .dark .premium-card {
            background: rgba(15, 23, 42, 0.9); /* Fond sombre en dark mode */
        }
        
        /* En-tête */
        .premium-header {
            background: linear-gradient(135deg, #4a6fa5 0%, #3a5a8a 100%);
            padding: 2rem;
            text-align: center;
        }
        
        .dark .premium-header {
            background: linear-gradient(135deg, #2d3748 0%, #1a202c 100%);
        }
        
        /* Champs de formulaire - Version très visible */
        .premium-input {
            width: 100%;
            padding: 0.75rem 1rem;
            border: 2px solid #e2e8f0;
            border-radius: 8px;
            font-size: 1rem;
            transition: all 0.3s ease;
            background-color: white;
            color: #1a202c;
        }
        
        .dark .premium-input {
            background-color: #2d3748;
            border-color: #4a5568;
            color: white;
        }
        
        .premium-input:focus {
            border-color: #4a6fa5;
            box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.3);
            outline: none;
        }
        
        .dark .premium-input:focus {
            border-color: #63b3ed;
            box-shadow: 0 0 0 3px rgba(99, 179, 237, 0.3);
        }
        
        /* Bouton */
        .premium-btn {
            background: linear-gradient(135deg, #4a6fa5 0%, #3a5a8a 100%);
            color: white;
            padding: 0.75rem 1.5rem;
            border: none;
            border-radius: 8px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            width: 100%;
        }
        
        .premium-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(74, 111, 165, 0.3);
        }
        
        .dark .premium-btn {
            background: linear-gradient(135deg, #4299e1 0%, #3182ce 100%);
        }
        
        /* Messages d'alerte */
        .alert {
            padding: 1rem;
            border-radius: 8px;
            margin-bottom: 1.5rem;
            display: flex;
            align-items: center;
        }
        
        .alert-error {
            background-color: #fff5f5;
            border: 1px solid #fed7d7;
            color: #e53e3e;
        }
        
        .dark .alert-error {
            background-color: #742a2a;
            border-color: #742a2a;
            color: #fed7d7;
        }
        
        .alert-success {
            background-color: #f0fff4;
            border: 1px solid #c6f6d5;
            color: #38a169;
        }
        
        .dark .alert-success {
            background-color: #22543d;
            border-color: #22543d;
            color: #c6f6d5;
        }
        
        /* Icônes */
        .input-icon {
            position: absolute;
            right: 1rem;
            top: 50%;
            transform: translateY(-50%);
            color: #a0aec0;
        }
        
        .dark .input-icon {
            color: #718096;
        }
        
        /* Liens */
        .text-link {
            color: #4a6fa5;
            text-decoration: none;
            font-weight: 500;
        }
        
        .dark .text-link {
            color: #63b3ed;
        }
        
        /* Espacement et mise en page */
        .form-container {
            padding: 2rem;
        }
        
        .form-group {
            margin-bottom: 1.5rem;
        }
        
        .form-label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 500;
            color: #4a5568;
        }
        
        .dark .form-label {
            color: #a0aec0;
        }
        
        .required-field {
            color: #e53e3e;
        }