Working on my first website and am placing content with various lenghths (div name is advisingbasics) above a div called bottompanel. Is there a way to make the advisingbasics div determine how far down the bottompanel div is located on the page? I've messed around with absolute/relative positioning and changing the div height 10 100%, but can't come up with any solutions.

I can place each div manually on the page, but then I run into an issue when zooming in and out on the browser...the text in advisingbasics changes (and sometimes overlaps over the bottompanel). I put a border on the advisingbasics div to make a 3 column structure and would like the text to stay inside the border, but the text changes when zooming in and out on the browser.

Here is the link to what I'm working on. I am very new to programming and hope this made sense, thanks for any advice in advance!