CSS - blinking animation effect with keyframes rule

Question

@keyframes blinker {  
    50% { opacity: 0; }
}


&.aura-banner { 
    &.banner1 {
        animation: blinker 0.7s linear infinite;
        margin-top: 4.5%;
        margin-left: 74.7%;
    }
    &.banner2 {
        animation: blinker 1.7s linear infinite;
        margin-top: 7.6%;
        margin-left: 86.3%;
    }
    &.banner3 {  
        margin-top: 33%;
        margin-left: 88.7%; 
    }

}