一对一直播源码实现效果，点击容器内的图标，图标边框变成border 1px solid red，点击空白处重置

const box = document.getElementById('box');
function isIcon(target) {
  return target.className.includes('icon');
}

box.onClick = function(e) {
  e.stopPropagation();
  const target = e.target;
  if (isIcon(target)) {
    target.style.border = '1px solid red';
  }
}
const doc = document;
doc.onclick = function(e) {
  const children = box.children;
  for(let i; i < children.length; i++) {
    if (isIcon(children[i])) {
      children[i].style.border = 'none';
    }
  }
}