* Use escape-svg() function

* Update theming.md

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Fixes #26563, closes #26576, closes #29021.

Fixes IE.

Also use `viewBox` instead of `viewbox`.

Held babel back due to issues with `objectSpread`.

For some reason the old image was bad quality.

Change `word-break: break-word;` to `word-wrap: break-word;`

This was causing issues for RTL, see https://github.com/twbs/bootstrap/issues/28238

* Remove default kbd element shadow, simplify selector while here

* Add new -shadow-inset variable so our shadows match on .form-control's, .form-select's, and .progress's

* Reuse box-shadow variables for .dropdown's, .popover's, .toast's, .modal's, and .img-thumbnail's

swap jQuery's `trigger(...)` with the more verbose native `dispatchEvent(...)`, as the former may not always behave/bubble correctly (observed while trying to write unit tests for keyboard handling of ARIA tab navigation), which may lead to this test passing even though it fails in real usage.

While #28450 overhauled a ton of forms work, the  support for this custom file input was ineffective. This updates the selector to target the custom field and gray out the entire field.

Fixes #28176.