:root {
            --primary-color: #334D6C;
            --secondary-color: #2c3e50;
            --accent-color: #F97316;
            --light-bg: #f8f9fa;
            --text-color: #333;
            --border-color: #e9ecef;
        }

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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: var(--light-bg);
            color: var(--text-color);
            line-height: 1.6;
        }

        .doctorat-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Hero Section */
        .doctorat-hero {
            background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
            color: white;
            padding: 100px 0 60px;
            text-align: center;
        }

        .doctorat-hero-title {
            font-size: 2.8rem;
            font-weight: 800;
            margin-bottom: 20px;
        }

        .doctorat-hero-subtitle {
            font-size: 1.2rem;
            opacity: 0.9;
            max-width: 800px;
            margin: 0 auto;
        }

        /* Presentation Section */
        .presentation-section {
            padding: 80px 0;
            background: white;
        }

        .section-title {
            font-size: 2.2rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 40px;
            text-align: center;
            position: relative;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--accent-color);
            border-radius: 2px;
        }

        .presentation-content {
            font-size: 1.1rem;
            color: #5a5a5c;
            line-height: 1.8;
            text-align: justify;
        }

        .highlight-box {
            background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
            color: white;
            padding: 30px;
            border-radius: 15px;
            margin: 40px 0;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        }

        /* Laboratoires Section */
        .laboratoires-section {
            padding: 60px 0;
            background: var(--light-bg);
        }

        .laboratoires-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }

        .lab-card {
            background: white;
            padding: 30px;
            border-radius: 15px;
            box-shadow: 0 5px 20px rgba(0,0,0,0.08);
            border-left: 4px solid var(--accent-color);
        }

        .lab-title {
            font-size: 1.3rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 15px;
        }

        /* Axes Section */
        .axes-section {
            padding: 80px 0;
            background: white;
        }

        .axes-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 25px;
            margin-top: 40px;
        }

        .axe-card {
            background: var(--light-bg);
            padding: 25px;
            border-radius: 12px;
            border-top: 4px solid var(--accent-color);
            transition: all 0.3s ease;
        }

        .axe-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }

        .axe-number {
            display: inline-block;
            background: var(--primary-color);
            color: white;
            width: 30px;
            height: 30px;
            border-radius: 50%;
            text-align: center;
            line-height: 30px;
            font-weight: 700;
            margin-bottom: 15px;
        }

        .axe-title {
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--secondary-color);
            margin-bottom: 10px;
        }

        /* Thèses Section */
        .theses-section {
            padding: 80px 0;
            background: var(--light-bg);
        }

        .theses-table-container {
            background: white;
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
            margin-top: 40px;
            overflow-x: auto;
        }

        .theses-table {
            width: 100%;
            border-collapse: collapse;
            min-width: 800px;
        }

        .theses-table th {
            background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
            color: white;
            padding: 20px;
            text-align: left;
            font-weight: 600;
        }

        .theses-table td {
            padding: 18px 20px;
            border-bottom: 1px solid var(--border-color);
        }

        .theses-table tr:hover {
            background-color: rgba(52, 77, 108, 0.05);
        }

        .theses-table tr:last-child td {
            border-bottom: none;
        }

        /* Retombées Section */
        .retombees-section {
            padding: 80px 0;
            background: white;
        }

        .retombees-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
            margin-top: 40px;
        }

        .retombee-card {
            background: var(--light-bg);
            padding: 30px;
            border-radius: 12px;
            text-align: center;
            transition: all 0.3s ease;
        }

        .retombee-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        }

        .retombee-icon {
            font-size: 2.5rem;
            color: var(--accent-color);
            margin-bottom: 20px;
        }

        .retombee-title {
            font-size: 1.2rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 15px;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .doctorat-hero-title {
                font-size: 2.2rem;
            }
            
            .section-title {
                font-size: 1.8rem;
            }
            
            .laboratoires-grid,
            .axes-grid,
            .retombees-grid {
                grid-template-columns: 1fr;
            }
            
            .lab-card,
            .axe-card,
            .retombee-card {
                padding: 20px;
            }
            
            .theses-table th,
            .theses-table td {
                padding: 12px 15px;
            }
        }

        @media (max-width: 480px) {
            .doctorat-hero {
                padding: 80px 0 40px;
            }
            
            .doctorat-hero-title {
                font-size: 1.8rem;
            }
            
            .presentation-section,
            .laboratoires-section,
            .axes-section,
            .theses-section,
            .retombees-section {
                padding: 40px 0;
            }
        }