html,
body {
  width: 1280px;
  height: 800px;
  box-sizing: border-box;
  // 禁止推拽
  -webkit-user-select: none; /* Chrome/Safari */
  -moz-user-select: none; /* Firefox */
  -ms-user-select: none; /* IE10+ */
  user-select: none; /* Standard */
}