* Switch all font-sizes to use the mixin
* Add notice in coding-guidelines to use accessible font sizes
* Fix label alignment in forms with big font-sizes
* Fix Stripe input boxes font-size not being responsive
* Fix select overflowing in small font sizes
* Add rem function from woocommerce/woocommerce-blocks#2320
* Make the font-size() mixin set relative line-height values
* Convert several magic numbers to use the new mixins
* Update docs
* Update input/select paddings to use the rem mixin
* Add lineHeight comment
* Interpolate rem() mixin inside calc
* Make input padding use only relative units
* Move no-shipping-placeholder to block - allow pointer events
* Allow payments placeholder to have pointer events
* Enable pointer events for children
* Wrap checkout with disabled