body{
margin:0;
font-family:"PingFang SC","Microsoft YaHei";
background:#f5f7fb;
color:#333;
}

header{
background:linear-gradient(135deg,#667eea,#764ba2);
color:white;
padding:70px 20px;
text-align:center;
}

nav{
background:#222;
padding:15px;
text-align:center;
}

nav a{
color:white;
margin:0 15px;
text-decoration:none;
font-size:16px;
}

.container{
max-width:1100px;
margin:auto;
padding:40px 20px;
}

.card{
background:white;
padding:30px;
border-radius:10px;
box-shadow:0 10px 25px rgba(0,0,0,0.08);
margin-bottom:30px;
}

.grid{
display:grid;
grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
gap:20px;
}

.item{
background:#f6f8ff;
padding:25px;
border-radius:8px;
text-align:center;
}

footer{
background:#1e1e1e;
color:#aaa;
text-align:center;
padding:25px;
margin-top:40px;
}