Fallback alignment - MDN Web Docs Glossary: Definitions of Web-related terms 编辑

In CSS Box Alignment, a fallback alignment is specified in order to deal with cases where the requested alignment cannot be fullfilled. For example, if you specify justify-content: space-between there must be more than one alignment subject. If there is not, the fallback alignment is used. This is specified per alignment method, as detailed below.

First baseline

start

Last baseline

safe end

Baseline

start

Space-between

flex-start (start)

Space-around

center

Space-evenly

center

Stretch

flex-start (start)

Learn more

• CSS Box Alignment