Application Question About Excel for Mac

Here is a problem I'm having with adding a line border or line in Excel for Mac 2011.
I have two pages in Layout view, one page below another page.

I want to add a full line border around the top page and a full border around the bottom page.

After the full line border around the first page is complete, and I attempt to add a full line border around the second page, the bottom line on the first page disappears. So the bottom line or bottom group of cells on the first page and the first line or top group of cells on the second page seem to be in conflict with one another.

Thanks for any tips on how to solve this problem so that a full line border can be added individually to the first and second pages.

Skip a row. You'll have a parallel line border where the pages meet. Make that skipped row shorter or taller so that you don't get two lines at the bottom of page one or the top of page two.

Alternatively, place the pages side by side and skip a column. There will be more flexibility with the column width and margins this way.