* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

body {
    background: linear-gradient(to bottom, #54a1f4, #b620f6);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.wave {
    position: relative;
}

.wave span {
    position: relative;
    display: inline-block;
    font-size: 40px;
    color: #ffffff;
    text-transform: uppercase;
    animation: flip 2s infinite;
    animation-delay: calc(.2s * var(--i))
}

@keyframes flip {

    0%,
    80% {
        transform: rotateY(360deg)
    }
}