LONDON--Steve Nicks' Edge of Seventeen provided the arc in Topshop Unique's Spring 2011 runway soundtrack. And it was wholly appropriate. Styled by Katie Grand, the girls were '70s all the way. We loved the 'fros, but our favorite pieces were the sheer, flowy pants, long suit jackets and a berry sweater and hot pants set that looked innocent in a sea of sex and rock 'n roll.