4 Solutions for Full-Screen Background Images - Paper Leaf
How to Make CSS Background Image Fit to Screen | Create a Responsive CSS Background Image - YouTube
Free download CSS background image to fit width height should auto scale in [4064x2704] for your Desktop, Mobile & Tablet | Explore 42+ Fit Background | Fit Desktop Wallpaper to Screen, Fit
How to Resize Images Using CSS for Responsive Web Design
html - How to resize an image to always fit all screen sizes (eg. Bootstrap 4)? - Stack Overflow