CSS3实现边框线条动画特效

<div class="box-line"></div>

CSS代码

.box-line, .box-line::before, .box-line::after {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

.box-line {
    width: 200px;
    height: 200px;
    margin: auto;
    background: url("img/Button-White-Large.png") no-repeat 50%/70% rgba(0, 0, 0, 0.1);
    color: #69ca62;
    box-shadow: inset 0 0 0 1px rgba(105, 202, 98, 0.5);
}
.box-line::before, .box-line::after {
    content: '';
    z-index: -1;
    margin: -5%;
    box-shadow: inset 0 0 0 2px;
    animation: clipMe 8s linear infinite;
}
.box-line::before {
    animation-delay: -4s;
}
.box-line:hover::after, .box-line:hover::before {
    background-color: rgba(255, 0, 0, 0.3);
}

@keyframes clipMe {
    0%, 100% {
        clip: rect(0px, 220.0px, 2px, 0px);
    }
    25% {
        clip: rect(0px, 2px, 220.0px, 0px);
    }
    50% {
        clip: rect(218.0px, 220.0px, 220.0px, 0px);
    }
    75% {
        clip: rect(0px, 220.0px, 220.0px, 218.0px);
    }
}