`{}`
`--paper-progress-transition-duration`           | Duration of the transition                  | `0.008s`
`--paper-progress-transition-timing-function`    | The timing function for the transition      | `ease`
`--paper-progress-transition-delay`              | delay for the transition                    | `0s`
`--paper-progress-container-color`               | Color of the container                      | `--google-grey-300`
`--paper-progress-active-color`                  | The color of the active bar