nav {
    z-index: 100;
    position: absolute;
    background-color: rgba(0, 0, 0, 0.783);
    top: 0;
    width: 100%;
    left: 0;
    height: fit-content;
    border-bottom: 3px dotted rgba(130, 130, 130, 0.355);
}
img {
    height: 60px;
    margin-top: 5px;
    vertical-align: middle;
    margin-bottom: 5px;
}
a {
    font-family: "Microsoft YaHei";
    font-size: 20px;
    font-weight: bold;
    color: darkcyan;
    vertical-align: middle;
    margin-left: 55px;
    text-decoration: none;
    
}

.link {
    border: 2px solid white;
    border-radius: 60px;
    background-color: white;
    padding-top: 5px;
    padding-bottom: 5px;
    padding-left: 13px;
    padding-right: 13px;
}

.link:hover {
    border: 2px solid white;
    border-radius: 60px;
    background-color: rgba(180, 180, 180, 0);
    padding-top: 5px;
    padding-bottom: 5px;
    padding-left: 13px;
    padding-right: 13px;
}

a:hover {
    font-family: "Microsoft YaHei";
    font-size: 20px;
    font-weight: bold;
    color: lightblue;
    
}

a:visited {
    font-family: "Microsoft YaHei";
    font-size: 25px;
    font-weight: 100px;
}