background-coloror a text
text-shadowusing the element style editors
Ctrl + o
The device toolbar allows to simulate different screens / devices to test the responsive behavior.
Display the media-queries using the three dots menu
Show media queries
Simulate most popular phones and tablet on the market
Access the settings of the DevTools by pressing
F1 or by clicking on the three dots on the top right of the DevTools panel => Settings
The same panel allows to dock the DevTools on different sides of the browser or having it on a separate window.
Change the theme (light / dark) on the settings
Disable the cache when the Dev tool is opened. It will prevent the browser to keep and render older content.
Read more on the official documentation