Genesis Grid - css styling issue

[makeitminnesota]

Hi, I am using the Gensis grid to display some custom taxonomies. My issue is I can't get a margin on the right side of the 2nd column so the colored box does not push up agains the sidebar like it is currently doing. Here is the page:

http://makeitus.com/businesscategory/metro/

Also, I want to make the headlines smaller in the boxes and I can't seem to get that to specify either. Suggestions? Here is my current css for the grid:

/* CSS for Genesis Grid Loop
------------------------------------------------------------ */
.genesis-grid-even {
float: right;
padding: 15px;
width: 45%;
background-color: #FFC;
margin-right: 10px;
}


.genesis-grid-even h1, h2, h3 {
font-size: 14px;
font-weight: bold;
}

.genesis-grid-odd {
clear: both;
float: left;
padding: 15px;
width: 45%;
background-color: #FFC;
margin-right: 10px;
}
.genesis-grid-even,
.genesis-grid-odd {
margin: 0 0 20px;
}


Thanks for any insight!