static/css/style.css

/* Fade-in animation */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to   { opacity: 1; transform: translateY(0); }
  }
  .message {
    animation: fadeIn 0.3s ease-out;
  }
  /* Typing indicator */
  .typing {
    width: 24px;
    height: 24px;
    position: relative;
  }
  .typing span {
    display: block;
    width: 6px; height: 6px;
    background: #4B5563;
    border-radius: 50%;
    position: absolute;
    bottom: 0;
    animation: bounce 0.6s infinite ease-in-out;
  }
  .typing span:nth-child(1) { left: 0; animation-delay: 0s; }
  .typing span:nth-child(2) { left: 9px; animation-delay: 0.2s; }
  .typing span:nth-child(3) { left: 18px; animation-delay: 0.4s; }
  
  @keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50%     { transform: translateY(-6px); }
  }