NEW YORK, Aug 24 (Reuters) - Retailers from Macy"s Inc (M.N) to Target Corp (TGT.N), keen to see the apparel sales momentum of the second quarter keep going, are stocking shelves not just with clothing for the office and school, but for a return to Zoom calls as COVID-19 infections surge in the United States. Retailers saw a spike in sales of dresses, sport coats and children"s clothing in the second quarter as pandemic restrictions lifted. Now, the rapid spread of the Delta variant in the United States is delaying the return to offices and threatening the return of in-person learning. Durand Guion, head of Macy"s fashion office, said that as customers continue to shop for "above-the-keyboard" clothing for video calls, they are also "trying to build a wardrobe to get back a bit of normalcy in their life," including styles for special occasions. Christina Hennington, Target"s executive vice president and chief growth officer, said on the company"s second-quarter earnings call that the discounter is preparing inventory for hybrid schooling environments after a strong start to the back-to-school season. "As college freshmen look to move on to campus for the first time, our merchandising and inventory plans account for the fact that many sophomores find themselves in that same position, having attended their first year of college in a completely virtual environment," Hennington told investors. According to research firm NPD Group, unit sales volume for U.S. apparel rose 12% in the second quarter of 2021 compared with pre-pandemic levels in 2019.Grade-school children are revamping their pandemic wardrobes with graphic tees and looser denim jeans, while parents" styles are merging business and comfort with "smart casual" dress shoes, blouses and slacks to mimic their hybrid remote-work schedules, said Keith Jelinek, managing director of the retail practice at Berkeley Research Group. Consumers are trickling back to the office seeking a wardrobe fit for corporate life, but comfortable enough for home offices, Kristen Classi-Zummo, an apparel analyst at NPD Group, said. White House Black Market"s senior vice president of design and merchandising, Kirsten Bowen, said shopping trends show customers "want to pull themselves together again." White House Black Market is owned by Chico"s FAS Inc (CHS.N). Male shoppers are also sprucing up with polo shirts, sport coats, trousers, denim and shoe purchases, Ralph Lauren CEO Patrice Louvet added in a post-earnings call. Hybrid work models have shifted office dress codes, according to a survey from NPD group. Thirty-five percent of U.S. consumers now have a casual dress code at work, a 7 percentage-point increase from pre-pandemic levels. Guion of Macy"s Inc said that as corporations continue to experiment with hybrid models, office clothing will "evolve over the next 12 to 18 months. It will not happen overnight."