Css design of hte webpage

body {
  width: 100%;
  min-height: 100vh;
  margin: 0;
  background: 
    linear-gradient(-45deg, transparent calc(50% - 1px), #111, transparent calc(50% + 1px)),
    linear-gradient(-45deg, transparent calc(55% - 1px), #111, transparent calc(55% + 1px));
    
  background-repeat: no-repeat;
  background-position: 0 0, 0 100%;
  background-size: 100% 40%, 100% 40%;
}