CSS @rule(At-rules)

@rule(at-rule　) with a keyword (a@Starting with a character (;) or the next declaration block (whichever comes first).

All content from the opening brace (

Rule	Description
`@charset`	Specify the character encoding of an external style sheet.
`@font-face`	Enable the use of downloadable web fonts.
`@import`	Import external style sheets.
`@keyframes`	Specify the value of animation properties for each point during the animation period.
`@media`	Set media type for a group of rules in a stylesheet.
`@page`	Define the size, orientation, and margins of the page box for the printing environment.

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