@container

@container is a CSS at-rule in the At-rules category. Applies styles based on container size rather than viewport. The syntax is @container <name> (<condition>) { /* rules */ }. A typical example: @container (min-width: 400px) { .card { flex-direction: row; } } It is commonly applied to markup such as <div class="demo">Sample</div> Browser support: Chrome 105+, Firefox 110+, Safari 16+, Edge 105+. A close relative is @media, which applies styles conditionally based on device features like viewport width. A close relative is @keyframes, which defines animation sequences with named keyframes. A close relative is @font-face, which defines custom fonts to be downloaded and used in the document. More about this category: CSS at-rules — @media, @keyframes, @font-face, @supports and more. Related At-rules entries: @media, @keyframes, @font-face, @import, @supports, @layer, @scope, @starting-style. This page is part of the free CSS Reference documentation covering 841+ properties, selectors, functions, and at-rules, each with syntax, values, examples, and browser support.