The “Quick settings” menu helps you access themes and other appearance tools a lot faster since most of these options were previously hiding in the full Settings menu.
Quick settings can be accessed by clicking the Settings cog. The panel offers quick access to interface choices such as Themes, Density and Inbox Type, and allows you to enable or disable features like Reading Panel and Email Threading with just a couple of clicks.
Quick settings also makes it possible to preview any changes in real time, helping you decide what works best without having to go back and forth between your Inbox and the Settings page. You can navigate to full settings by clicking the See all settings button at the top of the panel.
Other shortcuts that allowed you to customize your Gmail have been removed, including the option to edit your inbox layout by hovering over Inbox - this option is now accessible in the Quick Settings menu.