This is super fast and super light weight way to add some popups to your site. You can place anything inside popup. Also, it uses CSS browser technologies, so, you can combine it with different dynamic options and scripts
Check how it works
Additionaly, there is block Slide Panel/Popup which can be used to configure more options, for example, ability to set automatic trigger after period of time or Exit Intent.
For example, try to close this page or click on button below