body,
html {
    background-color: rgba(230, 240, 255, 1);
    background-image: url(./bg.png);
    background-repeat: no-repeat; /* 不重复 */
    background-size: cover; /* 拉伸铺满 */
    background-position: bottom; /* 居中显示 */
    height: 100%;
    width: 100%;
}
.body {
    text-align: center;
    padding: 0px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 100%;
    width: 80%;
}

.head * {
    vertical-align: middle;
    position: relative;
    z-index: 999;
}

.head > span > div:first-child {
    color: royalblue;
    font-size: 120%;
    font-weight: bolder;
}

.head > span > div:last-child {
    font-size: 100%;
}

.logo {
    height: 60px;
}

.body > img:first-child {
    width: 80%;
}

.body > img:first-child {
    width: 100%;
    min-height: 20vh;
}

.body > img:last-child {
    width: 10rem;
}