body{
    background: #ffefe1;
}
.nav{
    width: 1200px;
    height: 40px;
    line-height: 40px;
    margin: auto;
    text-align: center;
}
a{
    color: #000;
    text-decoration: none;
    padding: 0 20px;
}
.tb{
    width: 1200px;
    margin: auto;
}
.ava{
    width: 60px;
    height: 60px;
    vertical-align: middle;
}