only set a height value on the .progress, so if you change that value the inner .progress-bar will automatically resize accordingly.
To ensure that the label text remains legible even for low percentages, consider adding a min-width to the progress bar.
Use background utility classes to change the appearance of individual progress bars.
Add .progress-bar-striped to any .progress-bar
to apply a stripe via CSS gradient over the progress bar’s background color.
Add .progress-bar-animated to .progress-bar
to animate the stripes right to left.
Include multiple progress bars in a progress component if you need.