.header {
    font-family: Helvetica Neue, Helvetica, PingFang SC, Hiragino Sans GB, Microsoft YaHei, Noto Sans CJK SC, WenQuanYi Micro Hei, Arial,sans-serif;
    overflow: hidden;
    width: 100%;
    height: 55px;
    background-image: url("../img/header.png");
    background-repeat: no-repeat;
    background-position: 5%;
    position: fixed;
    top: 0px;
    left: 0px;
    z-index: 10;
    position: sticky;
}

div {
    display: block;
}

.nav {
    overflow: hidden;
    width: 100%;
    background-color: #1379da;
    position: sticky;
    top: 55px;
    left: 0px;
    z-index: 10;
}

.nav button {
    font-family: Helvetica Neue, Helvetica, PingFang SC, Hiragino Sans GB, Microsoft YaHei, Noto Sans CJK SC, WenQuanYi Micro Hei, Arial,sans-serif;
    background-color: inherit;
    color: white;
    height: 25px;
    float: none;
    border: none;
    outline: none;
    cursor: pointer;
    margin: auto;
    padding: 0px 16px;
    transition: 0.3s;
}

.nav button:hover {
    /* background-color: #ddd; */
    color: rgb(0, 183, 255);
}

#divframe {
    align-content: center;
    float: none;
}

.content {
    width: 100%;
    padding: 0 16px;
    margin-right: 0;
    display: grid;
    grid-template-columns: auto auto auto;
}

#main {
    width: 80%;
    margin: auto auto;
    padding-left: 10px;
    padding-right: 10px;
    overflow: auto;
    float: none;
    position: relative;
}

.tabs {
    width: 100%;
    text-align: right;
    display: none;
}

.tabs button {
    background-color: #a4d3ff;
    float: none;
    border: white solid 1px;
    outline: none;
    cursor: pointer;
    display: block;
    width: 100px;
    height: 25px;
    transition: 0.3s;
}

.section {
    width: 28%;
    height: 80px;
    float: left;
}

a.item {
    margin: 0 8px 10px 0;
    background-color:rgb(178, 217, 233);
    text-align: left;

    border-radius: 5px;
    padding: 6px 16px;
}

a.item strong {
    display: block;
    text-align: left;
}

.grid-container {
    /* display: grid;
    grid-template-columns: 15% 85%; */
    padding: 10px;
    max-width: 800px;
    margin: 0 auto;
}

.grid-item {
    padding: 20px;
}

a {
    text-decoration: none;
}

a:link, a:visited {
    color: black;
}

h4 {
    margin-top: 10px;
    margin-bottom: 10px;
    line-height: 1.1;
}