Sort the windows within the dock, and the browser will remember this order after you reload
You can hide the windows you don't want to see by clicking on the title bar
You can decrease or increase the size of the dialogue by grabbing the side or corner of any window and dragging
You can also undock and drag individual dialogues around by grabbing the dialoges by their titlebars
The state of the UI is stored in the browser's sessionStorage so it can be customized and those settings remembered across sessions. sessionStorage is removed when you close the current tab or browser window. CacheStorage is also used so the webapp is available offline. You can remove this data in the browser's settings.