It started with the Silicon Valley set, with their Steve Job’s-inspired Mom jeans and orthopaedic-looking All Bird trainers; went up a gear as street style and its attendant low-slung waistbands and chunky trainers invaded the red carpet and settled in for good as the world burrowed in during Covid, taking Zoom meetings in sweatpants and sheepskin slippers. A style we're calling ‘deep casual’ has emerged.