#main_div{
	/*background-color:#FFD700;*/
	width:600px,
}

#logo_div{
	/*background-color:#FFD700;*/
	height:200px;
	width:150px;
	float:left;
	
	display: flex;
	justify-content: center;
	align-items: center;

}

#logo_img{

	width:80%;
	text-align: center; 
	border-radius:20px; 
}

#introduce_div{
	/*background-color:#EEEEEE;*/
	height:200px;
	width:400px;
	float:left;
	display: flex;
	padding-left: 10px;
	/*justify-content: center;*/
	align-items: center;
}
#introduce_p{
	font-size:30px;
}

#download_div{
/*	background-color:#EEEEEE;*/
	height:200px;
	width:200px;
	float:left;

	display: flex;
	justify-content: center;
	align-items: center;
}

#download_a{
background-color:#09f;
width:100%;
height: 60px;
line-height: 60px;
border-radius:20px;

font-size:30px;
color: #000;
text-decoration:none;
text-align: center; 

}