transform-box

**transform-box**属性定义了与 transform、transform-origin 这两个属性有关联的布局框。

/* Keyword values */
transform-box: border-box;
transform-box: fill-box;
transform-box: view-box;

/* Global values */
transform-box: inherit;
transform-box: initial;
transform-box: unset;

transform-box属性被指定为以下所列出的关键字值之一。

border-box

border box 是用作引用框，一个表格（table）的 border-box 是 table 包装盒的边框，而不是表的边框。

fill-box

Uses the object bounding box as reference box.

view-box

Uses the nearest SVG viewport as reference box. If a viewBox attribute is specified for the SVG viewport creating element, the reference box is positioned at the origin of the coordinate system established by the viewBox attribute and the dimension of the reference box is set to the width and height values of the viewBox attribute.

transform-box = 
  content-box  |
  border-box   |
  fill-box     |
  stroke-box   |
  view-box     

• Using CSS Transforms (en-US)