.main{
    border:2px solid black;
    margin: 15px auto;
    padding: 0 15px 15px 15px;
    text-align:center;
    box-sizing:border-box;
    max-width:350px;
    width:90%;
}

.main input,
.main button {
    width: 90%;  
    margin: 5px 0;
    box-sizing: border-box;
}

.question{
    font-size:20px;
    font-weight:bold;
}