Webdesign Background ideas
How to Create a Responsive Full Background Image Using CSS
https://www.webfx.com/blog/web-design/responsive-background-image/
38 JavaScript Background Effects
https://freefrontend.com/javascript-background-effects/
HTML How to set a background image? – Full-page background image
https://codeberryschool.com/blog/en/html-how-to-set-a-background-image/