CSS - CSS Containing Block
CSS Containing Block
The containing block of the root element (aka initial block) is specified by the user agent. It is also a html element. Most browsers use rectangle size of the view port as an initial element. The element containing block with static or relative value attributed to the position property is set by the content edge of the table cell, of the nearest block-level or of the inline-block ancestor box. However, the containing block with an absolute value of the position property is formed by the nearest ancestor different from the static position.