Div向下移动而不是隐藏

您可以white-space: nowrap在容器上使用:https://jsfiddle.net/1631rrpn/3/

#container {
  width: 500px;
  height: 150px;
  border: 1px solid #ccc;
  overflow: hidden;
  white-space: nowrap;
}
#first {
  width: 500px;
  height: 100px;
  background: #666;
  display: inline-block;
}

#second {
  width: 100px;
  height: 100px;
  background: #ccc;
  display: inline-block;
}