[csswg-drafts] Browser zoom unit for accessibility [css-values-and-units] (#6869)

scottkellum has just created a new issue for https://github.com/w3c/csswg-drafts:

== Browser zoom unit for accessibility [css-values-and-units] ==
Currently all browsers scale the size of a pixel in order to zoom into a page by default. As a result, a zoomed in viewport is indistinguishable from a narrower viewport. This may result in unintended layout shifts as media queries are triggered as well as problems scaling responsive typography to be compatible with [SC 1.4.4](https://w3c.github.io/wcag/21/guidelines/#resize-text).

CSS authors need a way to identify zoom level so that we can create affordances for accessibility issues that may arise as a result of how zoom is currently implemented.

Two possible solutions:

1. A CSS keyword value that is effectively a unitless scale factor and can be used in calc functions.
```css
h1 {
  font-size: calc(6vw * zoom);
}
```
2. Setting a standard for browsers to zoom the root font size instead of the size of a pixel. This will enable people to have finite control over what scales using relative units. Scale factor can be discovered with `calc(1rem / 16px)`.
Note: I don’t expect this to be an acceptable solution as the web has tried this and moved away from it to create a more consistent experience as many websites don’t use relative units.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6869 using your GitHub account


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Received on Wednesday, 8 December 2021 21:30:40 UTC