It may be just me, though I seem to see the "other" part of the shadow of the arrow (the one backward).
Using:
.linktree:after {
box-shadow: -1px 1px 0 0px rgba(204, 204, 204, 0.9);
}
Instead of the original:
.linktree:after {
box-shadow: -1px 1px 0 1px rgba(204, 204, 204, 0.9);
}
seems to remove it.
I'm not sure if this breaks other things though...