/* Tùy chỉnh thanh cuộn cho giao diện tối */
        #chat-messages::-webkit-scrollbar {
            width: 8px;
        }
        #chat-messages::-webkit-scrollbar-track {
            background: #1f2937; /* bg-gray-800 */
        }
        #chat-messages::-webkit-scrollbar-thumb {
            background: #4b5563; /* bg-gray-600 */
            border-radius: 4px;
        }
        #chat-messages::-webkit-scrollbar-thumb:hover {
            background: #6b7280; /* bg-gray-500 */
        }
        /* Hiệu ứng gõ phím */
        .typing-indicator span {
            display: inline-block;
            width: 8px;
            height: 8px;
            border-radius: 50%;
            background-color: #9ca3af; /* text-gray-400 */
            animation: bounce 1.4s infinite ease-in-out both;
        }
        .typing-indicator span:nth-child(2) {
            animation-delay: -0.32s;
        }
        .typing-indicator span:nth-child(3) {
            animation-delay: -0.16s;
        }
        @keyframes bounce {
            0%, 80%, 100% { transform: scale(0); }
            40% { transform: scale(1.0); }
        }
        .message-image {
            max-width: 100%;
            border-radius: 1rem;
        }