main {
    display: flex;
    align-items: center;
    justify-content: center;
}

form {
    background: #fff;
    padding: 0;
    box-shadow: 10px 10px 30px rgba(30,42,61,.15);
    border-radius: 4px;
    overflow: hidden;
    width: 500px;
}
form h2 {
    font-size: 1.2em;
    margin: 0;
    padding: 5px 15px;
    background: #333;
    color: #fff;
    text-align: center;
}
form div.form {
    padding: 40px;
    text-align: center;
}
form div.form input[type=text] {
    padding: 0 15px;
    display: block;
    width: 100%;
    height: 40px;
    margin: 5px 0;
    text-align: center;
    border-radius: 20px;
    border: solid 1px #333;
}
form div.form input[type=submit] {
    padding: 0 35px;
    display: inline-block;
    width: auto;
    margin: 5px 0;
    text-align: center;
    border-radius: 20px;
    height: 40px;
    border: solid 1px #333;
    background: #333;
    color: #fff;
    transition: all 0.5s ease;
}
form div.form input[type=submit]:hover {
    background: #fff;
    color: #333;
    transition: all 0.5s ease;
}