@media ( min-width : 770px ){
	.chia{
		margin-right: 20px;
		max-width: 250px;
		height: 450px;
	}
}
@media ( min-max : 640px ){
		x{
			display: none;
		 }
	.chia{
		max-width: 400px;
	}
}
.chia{
	border:2px solid #666;
	margin-bottom: 25px;
	float: left;
	background-color: rgba(237, 237, 188, 1);
}
.chiacot {	
	display: block;
	margin: 0 auto;
}
#trai {
	display: block;
  width: 50%;
  float: left;

}
.tencot{
	margin: 3px;
	font-size: 16px;
	font-weight: bold;
	width: 100%;
	background-color: rgba(176, 176, 176, 0.75);
}
#chia1 {
  width: 25%;
  float: left;
}
#chia2 {
  width: 35%;
  float: left;
}
#chia3 {
  width: 40%;
  float: left;
}