html, body, main {
    min-height: 100%;
    height: 1px;
}
main {
    background: #efefef;
}
.container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100%;
}
.login {
    max-width: 400px;
    min-width: 200px;
    padding: 20px;
    border: 1px solid #cfcfcf;
    border-radius: 10px;
    background: #fff;
}
form {
    display: flex;
    flex-direction: column;
}
img {
    flex-grow: 0;
    width: 175px;
    align-self: center;
}
h1 {
    text-align: center;
    font-size: 2rem;
}