#1 Render collapseBox need two flex mode

[CPES]

When the tag collapseBox is resized, the mode of spaca management has to be different if the box is collpased or viewed.

The collpase button are to keep a minimal size and less flex of open boxes.

A solution is perhaps to use different flex for the component button or underlayed box (use this flex if uncollapsed)

[CPES]

example with to expand collapse button