yt-fadeInChatMessage.user.css

/* ==UserStyle==
@name           YouTube: fadeInChatMessage
@namespace      github.com/openstyles/stylus
@version        0.1.2
@description    To fade in Chat Messages (with YouTube Super Fast Chat)
@author         CY Fung
@preprocessor   stylus
@var number     from-opacity              "From Opacity"                  [0.3, 0, 1, 0.05]
@var number     to-opacity                "To Opacity"                    [1, 0, 1, 0.05]
@var number     fade-duration             "Fade Duration"                 [350, 10, 900, 10, 'ms']
@var select     timing-fx                 "Timing Fx"                     {
"cubic-bezier(.4,.9,.5,1)": "cubic-bezier(.4,.9,.5,1)",
"linear": "linear",
"ease-in-out": "ease-in-out"
}
==/UserStyle== */

@-moz-document url-prefix("https://www.youtube.com/live_chat") {
    
    
    if 1 {
        $animation = fadeInChatMessage fade-duration timing-fx 0s 1 normal forwards
    }
    
    @keyframes fadeInChatMessage {
        from{
            opacity:from-opacity;
        }
        to{
            opacity:to-opacity;
        }
    }


    .cyt-chat-last-message {

        animation: $animation;
    }
    
    /* Insert code here... */
}