html - Include padding in size of div - Stack Overflow
Box model
Box model
Control an element's width and height - Create Web Page Layouts With CSS - OpenClassrooms
Since you can control all 4 sides of a element using padding and margin, can I turn a rectangle element into a triangle or even a circle using padding and margin with
How To Adjust the Content, Padding, Border, and Margins of an HTML Element With CSS | DigitalOcean
CSS margin vs padding explained - Nathan Sebhastian