browser: >
Edge
summary: >
- Fire a [`transitioncancel` event](https://developer.mozilla.org/en-US/docs/Web/Events/transitioncancel) when a CSS transition is canceled
+ Fire a [`transitioncancel` event](https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/transitioncancel_event) when a CSS transition is canceled
upstream_bug: >
UserVoice#15939898
origin: >
## Changing the separator
-Separators are automatically added in CSS through [`::before`](https://developer.mozilla.org/en-US/docs/Web/CSS/::before) and [`content`](https://developer.mozilla.org/en-US/docs/Web/CSS/content). They can be changed by changing `$breadcrumb-divider`. The [quote](https://sass-lang.com/documentation/Sass/Script/Functions.html#quote-instance_method) function is needed to generate the quotes around a string, so if you want `>` as separator, you can use this:
+Separators are automatically added in CSS through [`::before`](https://developer.mozilla.org/en-US/docs/Web/CSS/::before) and [`content`](https://developer.mozilla.org/en-US/docs/Web/CSS/content). They can be changed by changing `$breadcrumb-divider`. The [quote](https://sass-lang.com/documentation/functions/string#quote) function is needed to generate the quotes around a string, so if you want `>` as separator, you can use this:
```scss
$breadcrumb-divider: quote(">");
### Navbar Dropdowns
-The `.dropdown-backdrop` element isn't used on iOS in the nav because of the complexity of z-indexing. Thus, to close dropdowns in navbars, you must directly click the dropdown element (or [any other element which will fire a click event in iOS](https://developer.mozilla.org/en-US/docs/Web/Events/click#Safari_Mobile)).
+The `.dropdown-backdrop` element isn't used on iOS in the nav because of the complexity of z-indexing. Thus, to close dropdowns in navbars, you must directly click the dropdown element (or [any other element which will fire a click event in iOS](https://developer.mozilla.org/en-US/docs/Web/API/Element/click_event#Safari_Mobile)).
## Browser zooming
## CSS variables
-Bootstrap 4 includes around two dozen [CSS custom properties (variables)](https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_variables) in its compiled CSS. These provide easy access to commonly used values like our theme colors, breakpoints, and primary font stacks when working in your browser's Inspector, a code sandbox, or general prototyping.
+Bootstrap 4 includes around two dozen [CSS custom properties (variables)](https://developer.mozilla.org/en-US/docs/Web/CSS/Using_CSS_custom_properties) in its compiled CSS. These provide easy access to commonly used values like our theme colors, breakpoints, and primary font stacks when working in your browser's Inspector, a code sandbox, or general prototyping.
### Available variables