"Let us prepare our minds as if we'd come to the very end of life. Let us postpone nothing. Let us balance life's books each day ... The one who puts the finishing touches on their life each day is never short of time."
Seneca

@media

The @media CSS at-rule can be used to apply part of a style sheet based on the result of one or more media queries. With it, you specify a media query and a block of CSS to apply to the document if and only if the media query matches the device on which the content is being used.
@media css reference