body {
  background: repeating-linear-gradient(
    45deg,
    #eee,
    #eee 10px,
    #fff 10px,
    #fff 20px
  );
  margin: 0;
  padding: 0;
}
.filler {
  background: repeating-linear-gradient(
    45deg,
    #606dbc,
    #606dbc 10px,
    #465298 10px,
    #465298 20px
  );
  box-sizing: border-box;
  color: white;
  display: block;
  height: 100%;
  padding: 3px;
}