Very good, well done.
You might want to do something about those content list image backgrounds though as they don't look right with your text in the images being clipped (see screenshot)... So maybe this will help...
.g-contentlist .g-contentlist-img {
background-size: contain;
background-position: 0px 10px;
}
To create a custom CSS compatible with Gantry 5 please read this
http://docs.gantry.org/gantry5/tutorials/adding-a-custom-style-sheet
.
Remember to recompile CSS from base outline too.
Regards, Mark.