html,body{
    width:100%;
}
*{
    box-sizing: border-box;
}
body{
    width:100%;
    margin:0 auto;
    background-image:url(images/pas.jpg);
    background-size:50%;
    text-align:center;
    background-position: auto 50%;
}
.btn{
    padding:50px 0px;
    width:100%;
    margin:0 auto;
}
.pass{
    color:rgb(8, 8, 8);
    background-color:rgb(244, 244, 11);
    font-weight: bold;
    border-radius: 5px;
    border:solid 1px;
}
.pass:hover{
    background-color:pink;
    color:white;
    cursor: pointer;
    border:solid 1px red;
}