body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f8f8f8;
}

header {
    background-color: #333;
    color: white;
    padding: 1em;
    text-align: center;
}

nav a {
    color: white;
    margin: 0 1em;
    text-decoration: none;
}

nav a:hover {
    text-decoration: underline;
}

main {
    padding: 2em;
    max-width: 800px;
    margin: auto;
}

section {
    margin-bottom: 2em;
}

.beian {
    color:#fff;
   text-decoration: none;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1em 0;
    position: fixed;
    width: 100%;
    bottom: 0;
}