In lieu of a separate actual space, a separate conceptual space can help too. Recently I started making an active effort to shut work down. Write down closing thoughts for the day, close all tabs and open processes, shut it all down. Block off time in my calendar, and even if I have to stay online for something important, I still go through the "shtudown" routine with everything that isn't the urgent situation. That whay when the urgency resolves, I am ready to just drop it and walk away. Its not since I approached this more mindfully that I realized just how much I was letting it weigh on me.
On Windows 10 you can have separate virtual desktops. You can use win+tab to add and switch to one and then bring all of your work windows over to it. I used to use that when I began WFH but got out of the practice. You can switch between them by doing ctrl+win+left arrow or ctrl+win+right but be careful because some graphics drivers use ctrl+alt+left/right/up/down to rotate the screen and I've messed up my multi-desktop setup more than once by mistaking the key combo.
It's not as good as having a separate system for office work but you can conceptually separate what you are doing at least.
I have a separate work laptop from my employer, but if I didn't, I would just create another user account on my computer.
I try to keep work/personal data completely separated. No logging in to private email from work account, no hobby code and work code accessible for same user account. No Hacker News or other unrelated sites on work browser. Private matters during work hours done on my private phone.
I find this good for work/free time separation, and helps a lot with concentration too.
