解释下background-position

`background-position` 是用于设置元素背景图片位置的 CSS 属性。它可以设置背景图片在元素内的位置，以便更好地呈现页面效果。具体来说，`background-position` 属性接受两个值，第一个值是水平方向的位置，第二个值是垂直方向的位置，它们可以使用关键字（如 `left`，`center`，`right`，`top`，`bottom`）或像素、百分比等单位来表示。如果只设置一个值，则第二个值默认为 `center`。例如，`background-position: 10px 20px;` 表示背景图片在水平方向上偏移 10 像素，在垂直方向上偏移 20 像素。

相关问题

background-position

The background-position property in CSS sets the initial position of a background image or background color within an element. It is used to determine where the background image is positioned relative to the element's borders and content.

The value of background-position can be a single value or a pair of values, which represent the horizontal and vertical positions of the background image. For example, background-position: top right; positions the background image in the top-right corner of the element, while background-position: center center; centers the background image both horizontally and vertically.

The background-position property also supports keywords such as top, bottom, left, and right, as well as percentage values that represent the distance from the top and left edges of the element. Additionally, the property can be used with multiple background images, allowing each image to be positioned independently.

background-position-y

background-position-y是CSS属性中的一个，用于设置背景图像在垂直方向上的位置。它可以与background-position-x一起使用，来控制背景图像在元素内的位置。该属性的值可以是一个长度值、百分比值或关键字值。例如，background-position-y: center; 表示将背景图像在垂直方向上居中显示。