Template:4-7-8.css

.breath478 {
	position: absolute;
	top: 0;
	left: 0;
    width: 100vw;
    height: 100vh;
    display: grid;
    overflow: hidden;
    justify-content: center;
    align-content: center;
    background-color:black;
}

.breath478 .circle {
    background-color: lightgray;
    width: 10vh;
    height: 10vh;
    border-radius: 5vh;
    display: block;
    animation: breath 19s ease infinite none running;
}

@keyframes breath {
    21%, 58% {
        background-color: lightblue;
        width: 50vh;
        height: 50vh;
        border-radius: 25vh;
    }
    58% {
        background-color: pink;
    }
}