I have been thinking about <body> classes, which would be useful here as well as several other scenarios. (Here's one implementation; I'm not at all sure it's the best one: https://stackblitz.com/edit/angular-change-body-css-class?file=src%2Fapp%2Fapp.component.ts)
With a class, it would be very easy to add a border (e.g. 5px black) to the whole screen, and a brief "This is a test system" at the top just above the nav bar.
I have been thinking about <body> classes, which would be useful here as well as several other scenarios. (Here's one implementation; I'm not at all sure it's the best one: https:/ /stackblitz. com/edit/ angular- change- body-css- class?file= src%2Fapp% 2Fapp.component .ts)
With a class, it would be very easy to add a border (e.g. 5px black) to the whole screen, and a brief "This is a test system" at the top just above the nav bar.