Why Show / Hide Elements leave a lot of space in-between sections of the page

Hi community,

Have tried to shorten the div block / container / sections in main webpage but not succeed. The Tablet / Mobile portrait screens are still displaying a very long an empty space after the hidden elements. How to get rid of a white blank in the middle, as there are other contents continuing in the page? Now it looks like something is missing.

Here is my site Read-Only:

If you fold/unfold elements by juggling between their Auto or given height and height:0, then white space will remain if you have given margins or paddings to those elements. When using fold/unfold IX, it’s a good practice to nest all your shrinkable elements inside of a div that has no margin or padding rules set. (or to not style the shrinkable element and use a div inside for content instead).