/* Ẩn thanh cuộn cho đẹp nhưng vẫn cuộn được */
#chat-box::-webkit-scrollbar {
    width: 6px;
}
#chat-box::-webkit-scrollbar-track {
    background: transparent;
}
#chat-box::-webkit-scrollbar-thumb {
    background-color: #cbd5e1;
    border-radius: 20px;
}
.typing-indicator span {
    display: inline-block;
    width: 6px;
    height: 6px;
    background-color: #94a3b8;
    border-radius: 50%;
    margin-right: 2px;
    animation: bounce 1.4s infinite ease-in-out both;
}
.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }
@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}