Horizontal scroll with anchor links - divs not scaling properly

I'm trying to use anchor links to trigger different horizontal scroll divs to appear.

I have a master container that holds multiple children: the children are all fixed width and height to fill the master container, with overflow-x enabled. Each child is stacked vertically on top of one another, so each jump link to a child reveals only that child:

https://i.imgur.com/ZUiUDKd.png

The children scale with their parent container, but the anchor point won't stay positioned to the top left of the parent container, thus revealing all of the hidden children when the window is scaled:

https://i.imgur.com/5emHc4O.gif

(https://jsfiddle.net/wpt9of8j/2/)

Fiddle is here. Any ideas on how I could go about fixing this (or getting a similar result using JS)?