.grid {
  margin: auto;
  display: block;
  position: relative;
}

@media screen and (min-width:1024px){
	.grid-sizer,
	.grid-item {
	  width: 25%;
	}
}

.grid-item {
  padding: 5px;
  box-sizing: border-box;
}

.grid-item img {
  width: 100%;
  height: auto;
  display: block;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

@media screen and (min-width:768px) and (max-width:1023px){
	.grid-sizer,
	.grid-item {
	  width: 33.33%;
	}
}

@media screen and (max-width:767px){
	.grid-sizer,
	.grid-item {
	  width: 50%;
	}
}