/* Container untuk Timeline */
        #timeline-wrapper {
            height: 90vh; /* Tinggi area scroll */
            overflow-y: scroll; /* Allow vertical scroll */
            background-color: #f0f2f5; /* Warna background ala Facebook */
            position: relative;
            padding: 20px 0;
        }

        /* Loading Indicator Styles */
        .loading-indicator {
            text-align: center;
            padding: 10px;
            display: none; /* Hidden by default */
            width: 100%;
        }

        /* Avatar styling */
        .instructor-img {
            width: 40px;
            height: 40px;
            object-fit: cover;
            border-radius: 50%;
            border: 2px solid white;
            margin-right: -10px; /* Overlapping effect */
        }
        
        .timeline-card {
            border: none;
            border-radius: 12px;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            margin-bottom: 20px;
        }

        .btn-group-custom .btn {
            font-size: 0.8rem;
            margin-bottom: 5px;
            display: inline-flex;
            align-items: center;
            gap: 5px;
        }