.colloque-header-block {
                text-align: center;
                margin-bottom: 30px;
                padding: 20px;
                background-color: #f9f9f9;
                border-radius: 8px;
                border-top: 4px solid var(--vert-officiel, #2e7d32);
            }
            .table-ronde-bloc {
                background: #ffffff;
                border: 1px solid #e0e0e0;
                border-radius: 8px;
                padding: 20px;
                margin-bottom: 20px;
                box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            }
            .table-ronde-titre {
                color: #1565c0;
                font-weight: bold;
                margin-bottom: 10px;
                font-size: 1.2em;
                border-bottom: 2px solid #64b5f6;
                padding-bottom: 5px;
            }
            .intervenants-liste {
                margin-top: 10px;
                padding-left: 20px;
                font-style: italic;
                color: #444;
            }
            .image-placeholder-affiche {
                background-color: #e3f2fd;
                border: 2px dashed #64b5f6;
                border-radius: 8px;
                padding: 40px 20px;
                text-align: center;
                margin: 20px 0;
                color: #1565c0;
                font-weight: bold;
            }
            .video-numero {
                display: inline-block;
                background-color: #1565c0;
                color: #ffffff;
                font-weight: bold;
                border-radius: 50%;
                width: 1.8em;
                height: 1.8em;
                line-height: 1.8em;
                text-align: center;
                margin-right: 8px;
            }
            .video-lien {
                margin-top: 10px;
            }