Flexbox lays out items in rows or columns with alignment and distribution — core modern CSS layout.
display:flex on a container with flex-direction, justify-content and align-items controls how children stretch and wrap. Flexbox excels at nav bars, card rows and vertical centering without float hacks.
Combine with CSS Grid for two-dimensional layouts. Tentaco Flexbox Generator outputs copy-paste CSS with live preview for prototyping.