Jumping page when scrolling

[keneso]

Hi

I think it’s a js script issue, if not my apologies for posting in the wrong section.

I have a page that when it has a certain height can’t get to the bottom of it 'cause it keeps jumping, if I add extra content, or padding to increase the height it scrolls fine to the bottom; basically there seems to be a critical value at which this happens, and obviously I can’t figure it out.
I think it has to do with the fixed nav script, but might easily be wrong.

Could you please take a look and tell me how I can fix it.

page is here
ttri dot biz/test_06

The monitor I am using is belinea 2025 s1 with 1280x1024 resolution and landscape orientation
os win 8.1

Thank you

[ralphm]

At a certain scroll point, the menu is given fixed positioning, which takes it out of the document flow, so the content below jumps up to fill the gap. It’s tricky to work around that. Perhaps you could add a script that detects the height of the menu, and then add that height value as a top padding value to the content div, to compensate for the empty space left by the removed menu.

[ralphm]

Or you could try faking something like this:

.fixed {
  position:fixed !important;
}

.header-bottom {
  position: absolute;
  width: 100%;
}

.content {
  padding-top: 4em;
}

[keneso]

Thank you.
Wish I had a 10th of your knowledge.
Your “fake” solution works.