html,
body {
    margin: 0;
    padding: 0;
}

/* 设置Header为Flex容器 */
header {
    display: flex;
    flex-direction: column;
    justify-content: center; /* 水平居中 */
    align-items: center; /* 垂直居中 */

}

header img {
    /*加圆角*/
    border-radius: 10px;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    display: flex;
    height: 77%;
    margin: 0 11.5%;
}

.left-nav {
    width: 20%;
    height: 100%;
    background-color: #f3f3f3;
    padding: 20px;

    /*加圆角*/
    border-radius: 10px;

}

.left-nav object {
    height: 100%;
}

.content {
    flex: 1;
}

.content object {
    width: 100%;
    height: 100%;
}

.headerObj {
    width: 100%;
    height: 88px;
}