html, body {
    width: 100%;
    height: 100%
}

body {

    background: url("../image/background.jpg") no-repeat;
    background-size: 100%;
}

/**渐变效果*/
.box {
    position: relative;
    /*width: 300px;*/
    /*height: 400px;*/
    /*display: flex;*/
    justify-content: center;
    align-items: center;
    background: #060c21;
}

.box:before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: #fff;
    z-index: -1;
}

.box:after {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: #fff;
    z-index: -2;
    filter: blur(40px);
}

.box:before, .box:after {
    background: linear-gradient(235deg, #89ff00, #060c21, #00bcd4);
}

.content {
    padding: 20px;
    box-sizing: border-box;
    color: #ffffff;
}