Tiffany Shively Demos couldn’t sleep Sunday night. But instead of draining her smartphone battery from the diminishing comfort of her bed, she got up and worked until 4 a.m. Monday on a project that has lately consumed huge swaths of the art, fashion and crafting worlds. “I wanted to create something other than the basic face-mask pattern,” said Shively Demos, a lawyer who also makes personalized Christmas stockings, lanyards and buttons under the name ModThirteen.