This seems to be an issue with one of the mixins you are using within your theme
mixin (I suspect it is with highlight
as that seems to be the only one dealing with font-family (mentioned in the trace of the error).
Removing the calls to those other mixins, this:
@mixin theme($name, $bgColor, $textColor) {
.#{$name}{
.content {
background: $bgColor;
color: $textColor;
}
}
}
@include theme("odd", 'blue', 'white');
Produces this:
.odd .content {
background: "blue";
color: "white";
}
Which seems to be what you want.