You two are a source of inspiration where otherwise there was very little 
This is âstockâ (base) cinnamon with the included Arc-Dark theme applied. Cromium you would need to install (it is what I use) but it has an arc dark theme which should be enabled by default since chromium uses the systems GTK theme YMMV.
And yes itâs become an excellent DE.
Just donât forget to set window effects off in effects otherwise you get transparency in the welcome screen buttons.
Edit: It doesnât happen in vbox because itâs using vbox drivers.
Yes the default cinnamon theme Adwaita causes this issue. Fortunately the devâs have included Arc-Dark which does not show this behavior. I use a fully AMD desktop system.
Thatâs strange because i found it happens on Arc dark also. If you hover on the welcome screen and or use it a lot it seems to show up for me. 
Thatâs Abyss Deep
Here we go ⌠
That is arc- dark.
I canât figure out what theme my Chromium is using. Even the window decorations look different than those I set in Cinnamon settings
How do I set it to the default GTK (3?) theme?
edit: the theme seems to be âArcâ as set in my ~/.config/gtk-3.0/settings.ini
but windows decorations are still a mystery to me
On that drop down to the right click on settings. Scroll down and you will see theme. There is a toggle box with an arrow in it. It should toggle between classic and gtk. You want gtk.
Thanks, I was indeed using the âClassicâ theme. But all the difference it made was to just turn my windowâs border to black
I also turned the option âUse system title bar and bordersâ on and now the border doesnât have decorations at allâŚ
Open a new tab I believe just the settings screen stays that way. 
And yes it can remove decorations if you want to increase vertical real estate on your screen.
Nope, it stays this way even when I open a new tab. I canât even close Chromium now, not having the âXâ at the right upper corner 
My i3 shortcuts donât work and new ones I am not used to yet.
Thatâs odd lol. I actually got called into work today (good thing). So i am not at a machine right now. If you close all the tabs it will close or right click the app in the menu bar and hit close.
Otherwise turn it back on in settings (three dots).
Seems I became confused here. My apologies. 
I can confirm that using the arc-dark theme and enabling use system title bar and borders does remove the buttons on the upper right of the window in chromium. When you open a new tab in chromium does the arc-dark theme apply as such?
I do not use Arc-dark, but (it seems) a regular ArcâŚ
This is my ~/.config/gtk-3.0/settings.ini
1 [Settings]
2 gtk-theme-name = Arc
3 gtk-icon-theme-name = ePapirus
4 # GTK3 ignores bold or italic attributes.
5 gtk-font-name = Fira Sans Compressed ExtraLight 12
6 gtk-menu-images = 0
7 gtk-button-images = 0
8 gtk-toolbar-style = GTK_TOOLBAR_TEXT
And as far as I can judge Chromium does use it. Only the window decorations look out of place, they were like that since i3wm. I was running it without decorations all together, maybe thatâs the reasonâŚ
The new Chromium window:
Yes you are correct there are several Arc, Arc-dark, Arc-darker for window decorations.
does it only work for decorations? I thought itâs responsible for overall look of the windows⌠If not, does it mean that my gtk-3.0 settings are incorrect?
Itâs not a big deal and everything seems to look (more or less) consistent across the apps, but I just need to learn how all this theming works 
edit: back at i3wm. And now Arc is used consistently even by Chromium.
I am lost why this isnât working with Cinnamon. But itâs not for this thread, so sorry for the noise 
edit2: and the answer was simple: Chromiumâs border-like thingy is set not by âWindow bordersâ entry in âThemesâ on Cinnamon, but by the âControlsâ one. Which was set to Adapta in my case. Itâs not a bug Iâm just a noob, donât mind me 
Absolutely nothing special this time:
Do you have this wallpaper somewhere around? I had it but I cannot find it anymore. Thanks in advance!