ArtMap | Spigot Plugin - Draw directly onto Minecraft maps | Video Game library

You have the following problems in your code:

1. You're trying to get the height value of all elements in $(".text-box") without iterating over it;
2. You're trying to use an inexistent innerHeight() function for those elements;
3. The same thing pointed out in the first item is happening when you try to set an attribute for the elements in $(".bg").

It looks like you really need to understand JavaScript fundamentals better.

In the code below, I iterate through the textboxes and gather the height value of each one of them inside an array. To get the values, I use the function getBoundingClientRect(). Then, I iterate through the newly created array to set the margin-top style for each .bg element, by means of the jQuery css() function.