Default progress bar.
Remove the <span> with sr-only class from within the progress bar to show a visible percentage.
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.
Add active to progress-bar-striped class to animate the stripes right to left. Not available in IE9 and below.
Place multiple bars into the same progress to stack them.