body {
  font-family: Arial, sans-serif;
text-align:center;
  Font-size:24px;
}

header {
  background-color: #;
  padding: 20px;
} 

main {
  text-align:center;
  width:100%;
  margin:0 auto;
}
/*@media screen and (min-width:1440px) and (max-width:1600px){}*/
@media screen and (min-width:1440px){ /*大于等于1440*/
  main {
  text-align:center;
  Width:800px;
  margin:0 auto;
} 
}

p{
   color:$ccc;
}
/* Add CSS */
nav {
  padding: 20px;  
}

nav a {
  color: #000;
  text-decoration: none;
  padding: 5px 10px;i
}
nav a.one{
  font-size: 24px;
    color: #ff3535;
    background: #fbe1e1;
    border-radius: 5px;
}
nav a:hover {
  background-color: #fff;
}

footer {
  text-align: center; 
  padding: 20px;
  font-size:18px;
}