If you've ever set an element to width: 300px and wondered why it ends up wider than 300px, you're not alone. One of the most important CSS concepts for beginners is the box model . Understanding it can save you a lot of time debugging overflowing cards, inputs, buttons, and layouts. The CSS Box Model Every HTML element can be thought of as a box made up of four main parts: Content Padding Border Margin The important part is understanding what happens whe...