对象上的流体和动态动画显示和消失（HTML / JS / CSS）

it's difficult to describe in the title,but what I'm thinking of are those sites like some of the Tumblrs or some other fancy webpages where the parts (for example the images) when they appear they move in next to the existing ones, you can move them and all the others move along and rearrange themselves. Same when some of the middle disappear and all the others rearrange and move into the space of the one that disappeard. it's difficult to describe in the title,but wh