CSS align-self – override align-items for flex-item

.someflexcontainer {
  display: flex;
  align-items: flex-start;
}
.flexitem {
  /* Override align-items for a specific flex-item */
  align-self: flex-end;
}

<style>
.fbox {
  display: flex;
  align-items: flex-start;
  width: 200px; background-color:gray;
}
.child {
  background-color:green;
  border: 1px solid black; padding: 5px;
}
</style>

<div class=fbox>
<div style="font-size:30px;" class="child">div1</div>
<div class="child">div2 longer text</div>
<div class="child">div3</div>
<div style="align-self:flex-end;" class="child">div4</div>
</div>