body {  
    font-family: Arial, sans-serif;  
    margin: 0;  
    padding: 0;  
    background-color: #f4f4f4;  
}  

h1.pageTitle {  
    background-color: #13b2a2;  
    color: #fff;  
    padding: 20px;  
    text-align: center;  
}  

h1 {  
    margin: 0;  
}  

main {  
    padding: 20px;  
    max-width: 800px;  
    margin: 0 auto;  
    background-color: #fff;  
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);  
    margin-bottom: 20px;  
}  

h2 {  
    margin-top: 0;  
}  

.app-container {  
    display: flex;  
    flex-wrap: wrap;  
    justify-content: space-around;  
}  

.app-card {  
    width: 200px;  
    margin-bottom: 20px;  
    text-align: center;  
}  

.app-card img {  
    width: 100%;  
    height: auto;  
    border-radius: 10px;
}  

.app-card h3 {  
    margin: 10px 0;  
}  

footer {  
    background-color: #333;  
    color: #fff;  
    padding: 10px;  
    text-align: center;  
}  

footer a{
    color: white;
}
.beian {
    font-size: small;
    text-align: center;
}

.beian img{
    width: 9px;
    height: 10px;
}