Please.....download and test this theme using GTK-3.20 -->> GTK-3.24+ for Gnome-Desktop and GTK-2.0 for XFCE Lovers :)
Also look all screenshot for detail.
Just extract this theme to get "MacBuntu-Flat" folder, then copy paste to your homedir file manager
[ /home/YOURNAME/.themes/ ]
Copy paste to root
[ /usr/share/themes/ ]
To Add the window buttons layout to the left side option, open a terminal:
gsettings set org.gnome.desktop.wm.preferences button-layout "close,maximize,minimize:"
To Add the window buttons layout to the right side, When you want to revert in normal option, open a terminal:
gsettings set org.gnome.desktop.wm.preferences button-layout ":minimize,maximize,close"
Please, Support & Votes this theme, Also all feedback, reports, correction are welcome!
Note: This theme actually not yet included "Gnome-Shell" theme, Because I still work on it :)