html{
    font-size: 62.5%;
}
.x{
    border-bottom: .25rem solid rgb(128, 124, 124);
}
h1{
    font-size:3.5rem;
    text-align: center;
    color:  rgb(128, 124, 124);
}
.y{
    display: flex;
    justify-content: space-around;
}
.yuanliao{
    font-size: 2.5rem;
    color:rgb(128, 124, 124);
}
.content{
    font-size:2rem ;
    color:rgb(128, 124, 124);
    margin: 0 auto;
    text-align: center;
}
.return{
    font-size: 4rem;
    margin:  0 auto;
    text-align: center;    
}
a{
    text-decoration: none;
    color:rgb(128, 124, 124) ;
}