#ch-app{
    max-width:700px;
    margin:40px auto;
    padding:20px;
    border:1px solid #ddd;
    border-radius:10px;
    background:#fafafa;
}
#ch-app input{
    width:70%;
    padding:10px;
    margin:10px 0;
}
#ch-app button{
    padding:10px 15px;
    background:#0b5ed7;
    color:#fff;
    border:none;
    cursor:pointer;
}