HTML and CSS use a box model, which means that page elements include margins, padding, background colors and, optionally, decorative borders. Open your HTML Web page in a text editor such as Notepad.

it builds on the CSS3 Box model module and adds functionality to flow the content of an element into multiple columns. Essentially, multi-column layouts provide a degree of flexibility allowing ...

Also, CSS Flexible Box Layout, which is a module of CSS that defines a CSS box model optimized for user interface design, and the layout of items in one dimension inched up 3% from last year and ...