body{background:#f1f1f1;font-family:Arial;margin:0;}
.mg-box{width:350px;margin:80px auto;background:#fff;padding:20px;border-radius:10px;text-align:center;}
input{width:90%;padding:10px;margin:10px 0;}
button{padding:10px 20px;border:none;background:#333;color:#fff;cursor:pointer;}
.err{color:red;}