.main-about-container{
    display: flex;
    flex-direction: column;
    /* height: 100%; */
}

.about-bg{
    /* flex: 1; */
    background-image: url('../img/about.png');
    background-size: 100% 100%;
    /* 背景图片将填充整个屏幕 */
    background-repeat: no-repeat;
    /* 背景图片不重复 */
    background-attachment: fixed;
    /* 背景图片固定，不随页面滚动 */
    width: 100%;
    /* height: 100%; */
    height: calc(100vh - 80px);
}