The Birkenstock trend has reached new heights in fashion this season. French designer Isabel Marant has launched her resort 2015 lookbook starring model Andreea Diaconu in slip-on sandals inspired by the German shoe. However, Marant’s studded detail and rich leather elevate the traditional Birkenstock style, tenfold. The relaxed-luxe collection of menswear-inspired outerwear, pleated skirts, and embellished shirt dresses emulate extreme comfort and cozy style, including her Marant’s fashionable flats.