@keyframes clippath {
    0%,
    100% {
        clip-path: inset(0 0 95% 0);
    }
    25% {
        clip-path: inset(0 95% 0 0);
    }
    50% {
        clip-path: inset(95% 0 0 0);
    }
    75% {
        clip-path: inset(0 0 0 95%);
    }
}

.item {
    width: 200px;
    height: 100px;
    position: relative;
    overflow: hidden;
    margin: 10%;
    border-radius: 4px;
    // background: #000;
    &::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        // background: red;
        border: 10px solid green;
        clip-path: inset(0 0 95% 0);
        clip-path: inset(0 95% 0 0);
        clip-path: inset(95% 0 0 0);
        clip-path: inset(0 0 0 95%);
        animation: clippath 3s infinite linear;
    }
}