利用渐变做出的背景，重复的时候是按照多大的尺寸重复，为什么背景由一个重复后就能形成那种纹理
csss3代码如下：
.div7{
width: 400px;
height: 150px;
margin: 10px;
background:
radial-gradient(circle at 50% 59%,
#D2CAAB 3%, #
364E27 4%, #364E27 11%, rgba(54,78,39,0) 12%, rgba(54,78,39,0)) 50px 0,
radial-gradient(circle at 50% 41%, #364E27 3%,
#D2CAAB 4%, #
D2CAAB 11%, rgba(210,202,171,0) 12%, rgba(210,202,171,0)) 50px 0,
radial-gradient(circle at 50% 59%,
#D2CAAB 3%, #
364E27 4%, #364E27 11%, rgba(54,78,39,0) 12%, rgba(54,78,39,0)) 0 50px,
radial-gradient(circle at 50% 41%, #364E27 3%,
#D2CAAB 4%, #
D2CAAB 11%, rgba(210,202,171,0) 12%, rgba(210,202,171,0)) 0 50px,
radial-gradient(circle at 100% 50%, #D2CAAB 16%, rgba(210,202,171,0) 17%),
radial-gradient(circle at 0% 50%, #364E27 16%, rgba(54,78,39,0) 17%),
radial-gradient(circle at 100% 50%, #D2CAAB 16%, rgba(210,202,171,0) 17%) 50px 50px,
radial-gradient(circle at 0% 50%, #364E27 16%, rgba(54,78,39,0) 17%) 50px 50px;
background-color :#63773F;
background-size: 100px 100px;
}