CSS At-Rules Reference

At-rules are used to convey metadata information, conditional information, or other descriptive information.

At-Rule	Description
@charset	Specifies the character encoding used in the style sheet
@font-face	Specifies a custom font to display text
@import	Imports another style sheet into the current style sheet
@keyframes	Specifies the animation code
@media	Sets the style rules for different media types/devices/sizes

Example

/* Example of @media rule */
@media screen and (max-width: 600px) {
  body {
    background-color: lightblue;
  }
}