.rightBoxContainer was removed from the rule where it is by default, but the editor left the comma after .leftBoxContainer, which invalidates the whole rule. None of this is currently being applied by this rule:
Code:
.leftBoxContainer, {
border: 1px solid #536EA6;
background-color: #B0C4DE;
margin-top: 2.1em;
}
Change it to this
Code:
.leftBoxContainer, .rightBoxContainer {
border: 1px solid #536EA6;
background-color: #B0C4DE;
margin-top: 2.1em;
}
or give each side its own rule if you want them different.
This doesn't address the "margin" appearance; there are several ways of doing that, depending on the exact look you want.