html {
  --s: 150px; /* control the size */
  
  background:
    linear-gradient(135deg,#0000 18.75%,#5E412F 0 31.25%,#0000 0),
    repeating-linear-gradient(45deg,#5E412F -6.25% 6.25%,#FCEBB6 0 18.75%);
  background-size: var(--s) var(--s); 
}