.center{
	text-align:center;
}
.center_box{
	margin-left:auto;
	margin-right:auto;
	width: max-content;
}
.float_left{
	float:left;
}
.float_right{
	float:right;
}
.clear{
	clear:both;
}
.oldyear{
	font-size:small;
}
@media screen and (min-width:640px) {
	.big_none{
		display: none;
	}
}
@media screen and (max-width:639px) {
	.mini_none{
		display: none;
	}
}
picture, img{
    max-width: 100vw;
    height:auto;
}