.logo_menu {
    width: 35px;
    border: 3px solid;
    border-image: linear-gradient(45deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    animation: border-rotate 4s linear infinite;
}

/* 定义动画 */
@keyframes border-rotate {
    0% {
        border-image: linear-gradient(0deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    }
    25% {
        border-image: linear-gradient(90deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    }
    50% {
        border-image: linear-gradient(180deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    }
    75% {
        border-image: linear-gradient(270deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    }
    100% {
        border-image: linear-gradient(360deg, #ff8a00, #e52e71, #9d50bb, #4a00e0) 1;
    }
}