.form {
    position: fixed;
    display: flex;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
}

form {
    width: 400px;
    max-width: 90%;
    padding: 30px;
    margin: auto;
}

form input {
    display: block;
    width: 100%;
    padding: 10px;
    margin-top: 30px;
    border: none;
    border-bottom: 4px solid #ccc;
}

button {
    display: block;
    width: 100%;
    padding: 10px;
    margin-top: 30px;
    background: #45B8E5;
    color: #ffffff;
    font-size: 1em;
    border: none;
    cursor: pointer;
    -webkit-border-radius: 4px;
    -moz-border-radius: 4px;
    border-radius: 4px;
}