How to change order in flex box with just CSS

Isn’t there a way to change the order of the children of a flex box with just CSS?

<div> flex 2 </div> <div>
flex 3
</div>
<div style="flex-order:-1"> flex 1 </div>

>Solution :

you can use the property order
.div1 { order: 0; }

But to make it work you should set order to all childrens

Also you should now: 0 for first position, and 1, 2 and so on for other positions