body {
    background-color: white;
    margin: 0;
    padding: 0;
}

html body {
    height: 100%;
}

/* 顶部 */
.nav {
    width: 100%;
    height: 100px;
    background-color: white;
    position: fixed;
    top: 0;
    z-index: 1;
    display: flex;
}

/* 内容 */
.main {
    width: 100%;
    height: 100%;
    margin-top: 125px;
    background: white;
    display: flex;
    justify-content: center;
}

/* 底部 */
.copyright {
    /* margin-top: 40px; */
    height: 100px;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #0068b6;
    color: white;
    position: fixed;
    bottom: 0;
}