body {

font-family:
Arial,
"Microsoft YaHei",
sans-serif;

max-width:900px;

margin:40px auto;

padding:20px;

line-height:1.8;

color:#333;

}



h1 {

font-size:42px;

}



h2 {

margin-top:20px;

}



.card {

border:1px solid #ddd;

border-radius:10px;

padding:25px;

margin:25px 0;

}



a {

color:#0366d6;

text-decoration:none;

}



footer {

margin-top:50px;

color:#777;

}