very simple layout creates unnecessary margin

[bzx]

Hello,

I am working on a very simple page layout example with Preboot's grid and right away it's creating unnecessary margin on right hand side, which causes vertical scrollbar to appear. I don't understand why the right margin is set like that.

Here's the example with default Preboot stylesheet (I skipped outer tags from HTML, and I'm using doctype for html5):

HTML:
<div class="wrap">
  <div class="main">main content</div>
  <aside>sidebar</aside>
</div>

CSS:
.wrap {
  .make-row();
}
.main {
  background: blue;
  .make-column(9);
}
aside {
  background: orange;
  .make-column(3);
}

[domicoeth]

I had this same problem briefly; you just need overflow:hidden on a wrapper around the row/s. It doesn't work on the a div with .make-row().