background-position的问题

Question

在w3中是这样定义background-position

其中第二句中讲到背景图片如果重复将从这一点开始。是什么意思？还有在背景图片中background-position: 20px -30px;其中负号是什么意思？

Answer 1

background_position属性有四个参数，分别为 上 右 下 左，如果只用两个参数则默认为 是： 上 右，同时 系统默认上下参数和左右参数一致。所以这里的-30是指左右方向的像素移动-30，你可以实际操作下看下效果.取300或者其他数据比较明显

Answer 2

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