CSS-only bottom-anchored scrolling area
Briefly

But you know, using JavaScript means it can fail, or can take a while to happen, potentially at a point where the user has begun scrolling in that region. Not perfect.
One thing worth mentioning is that using column-reverse creates a disconnect between the visual order and the DOM order, which can be confusing for screen-reader users.
Read at kittygiraudel.com
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