如何制作可拖拽的视频聊天容器？

<div id="chat-container"></div>

#chat-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 300px;
  height: 200px;
  background-color: #fff;
  border: 1px solid #ccc;
  cursor: move;
}

var container = document.getElementById('chat-container');
var isDragging = false;
var offsetX = 0;
var offsetY = 0;

container.addEventListener('mousedown', function(event) {
  isDragging = true;
  offsetX = event.clientX - container.offsetLeft;
  offsetY = event.clientY - container.offsetTop;
});

document.addEventListener('mousemove', function(event) {
  if (isDragging) {
    container.style.left = event.clientX - offsetX + 'px';
    container.style.top = event.clientY - offsetY + 'px';
  }
});

document.addEventListener('mouseup', function() {
  isDragging = false;
});