以下的.userinfo-avatar[size]中的[size]是啥意思啊?
.userinfo-avatar { width: 100rpx; height: 100rpx; margin: 20rpx; border-radius: 50%; background-size: cover; background-color: white; }
.userinfo-avatar[size] { width: 100rpx; }
.userinfo-avatar:after { border: none; }