@property

@property is a CSS at-rule in the At-rules category. Registers custom CSS properties with type checking and default values. The syntax is @property <name> { syntax: <string>; inherits: <boolean>; initial-value: <value>; }. A typical example: @property --my-color { syntax: "<color>"; inherits: false; initial-value: #c0ffee; } It is commonly applied to markup such as <div class="demo">Sample</div> Browser support: Chrome 85+, Firefox 128+, Safari 15.4+, Edge 85+. 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, @container, @layer, @scope. 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.