<!DOCTYPE html>
<style>
.flex {
   display: flex;
   flex-flow: row;
   align-items: baseline;
}
.block {
   background: grey;
   margin: 5px;
   padding: 5px 10px 10px 5px;
   width: 200px;
   writing-mode: vertical-lr;
}
.block > :nth-child(1) { font-size:48px; }
.block > :nth-child(2) { font-size:64px; }
.block > :nth-child(3) { font-size:96px; }
.block > :nth-child(4) { font-size:128px; }
.block > div {
   border-width: 4px 2px 2px 4px;
   border-style: solid;
   padding: 6px 4px 4px 6px;
   margin: 10px 4px 4px 10px;
}
</style>

<p>Vertical-LR flexbox with 1x4 with parallel items.<br>Items should use 'alphabetic' as dominant baseline for self-baseline alignment.</p>
<div class="flex block verticalLR"><div>A</div><div>A</div><div>A</div><div>A</div></div>