:root{--pm-s: 38%;--pm-t: 10%;--pm-b: 20%}.pm{--pm-side: linear-gradient(to right, transparent 0, #000 var(--pm-s));--pm-vert: linear-gradient(to bottom, transparent 0, #000 var(--pm-t), #000 calc(100% - var(--pm-b)), transparent 100%)}