.ch-grid {
	margin: 20px 0 0 0;
	padding: 0;
	list-style: none;
	display: block;
	text-align: center;
	width: 100%;
}

.ch-grid:after,
.ch-item:before {
	content: '';
    display: table;
}

.ch-grid:after {
	clear: both;
}

.ch-grid li {
	width: 220px;
	height: 220px;
	display: inline-block;
	margin: 20px;
}
@media screen and (max-width: 700px) { 
.ch-grid {
	margin: 20px 0 0 0;
	padding: 0;
	list-style: none;
	display: block;
	text-align: center;
	width: 100%;
}
   .ch-grid li {
	width: 150px;
	height: 150px;	
}
}
@media screen and (max-width: 400px) { 
  .ch-grid {
	margin: 20px 0 0 0;
	padding: 0;
	list-style: none;
	display: block;
	text-align: center;
	width: 100%;
}
.ch-grid li {
	width: 100px;
	height: 100px;	
}
}