Edit in JSFiddle

<div class="light-background"></div>
<div class="dark-background"></div>

html,body {
  padding:0;
  margin:0;
  height:100%;
  min-height:100%;
}
div{
  width:100%;
  height:50%;
}
/* Светлый фон */
.light-background{
  background: -moz-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%),-moz-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%);
  background: -webkit-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%),-webkit-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%);
  background: -ms-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%),-ms-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%);
  background: linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%),linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(0, 0, 0, 0.2) 50%,rgba(0, 0, 0, 0) 52%);
  background-size: 1em 1em;
  background-color: #fff;
}
/* Тёмный фон */
.dark-background {
  background-image: -moz-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 1) 50%,rgba(0, 0, 0, 0) 52%),-moz-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 1) 50%,rgba(0, 0, 0, 0) 52%);
  background-image: -webkit-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 1) 50%,rgba(0, 0, 0, 0) 52%),-webkit-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 1) 50%,rgba(0, 0, 0, 0) 52%);
  background-image: -ms-linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 0.1) 50%,rgba(0, 0, 0, 0) 52%),-ms-linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 0.1) 50%,rgba(0, 0, 0, 0) 52%);
  background-image: linear-gradient(45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 0.3) 50%,rgba(0, 0, 0, 0) 52%),linear-gradient(-45deg,rgba(0, 0, 0, 0) 48%,rgba(255, 255, 255, 0.3) 50%,rgba(0, 0, 0, 0) 52%);
  background-size: 1em 1em;
  background-color: #555;
}