I am a newbie designer and I'm working for a friend who wanted me to do the UI for their desktop web application. This is a B2B product wherein the customer will use the app to manage their storage spaces. Also, this is a desktop-first app since that's the main endpoint and a mobile app as separate, good to have feature.
The issue stems from the fact that when I had designed the screens, I used the full page size of 1920 x 1080(which I think is a safe size that accounts for most monitors out there). I did not account for the average usable area( area left after removing the Chrome/Firefox/Safari browser navbar and bookmarks bar) since that would keep changing depending on what the user uses. And post-development, when viewing the developed screens, most of the areas have a scroll bar on account for not fitting in the screen. I'm not sure on how to proceed from here other than doing a full rework of the designs since that is not an option at this moment and the product has to be released in a few months
I hope I have summarized the problem P.S. I have tried looking everywhere for this problem on how UI designers design their web app and couldn't find any material for it. Even when I see the designs online, its just the design and no navbars as such.
Edit 1: My concern is actually not about the resolution but how to design the page with respect to the available usable area. So my main concern is whether do you take the browser height into consideration while designing or do you just design for the whole resolution( 1920 x 1080) and let the front end dev take care of scaling it to fit the browser. When I spoke with the Front End guy yesterday, he told me the usable area is only 921px. So should I have designed my pages keeping that height as fixed? But that does not make sense since different browsers may have different heights? So how should I proceed in solving this?