body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: black;
}

.container {
    font-size: 10px;
    width: 40em;
    height: 10em;
    display: flex;
    justify-content: space-between;
}

.eye {
    box-sizing: border-box;
    width: 15em;
    border: solid white;
    border-width: 0 5em;
    border-radius: 50% 0;
    animation: blink 2s linear infinite;
}

@keyframes blink {
    40%, 60% {border-width: 0 5em;}
    50% {border-width: 0 7.5em;}
}

.eye.left {transform: rotate(25deg);}
.eye.right {transform: rotateY(180deg) rotate(25deg);}