Progress bars use CSS3 transitions and animations to achieve some of their effects. These features are not supported in Internet Explorer 9 and below or older versions of Firefox. Opera 12 does not support animations.
Content Security Policy (CSP) compatibility
If your website has a Content Security Policy (CSP) which doesn't allow
style-src 'unsafe-inline', then you won't be able to use inline
element.style.width) or using custom CSS classes.
Default progress bar.
.sr-only class from within the progress bar to show a visible percentage.
To ensure that the label text remains legible even for low percentages, consider adding a
min-width to the progress bar.
Progress bars use some of the same button and alert classes for consistent styles.
Uses a gradient to create a striped effect. Not available in IE9 and below.
.progress-bar-striped to animate the stripes right to left. Not available in IE9 and below.
Place multiple bars into the same
.progress to stack them.
35% Complete (success)
20% Complete (warning)
10% Complete (danger)