The old slider in the bottom bar is gone. But you can drag the page number indicator on the right side (in the Continuous page view mode) or at the bottom (in the Single Page view mode) to scroll pages quickly. You can also tap it to bring up the Go to Page dialog to jump to a specific page.
The current page number will be shown at the center of the screen.
Please feel free to provide feedback on the new user interface. Thank you.