html,
body {
    height: 100%;
    width: 100%;
    margin: 0;
    top: 0;
}

main {
    align-items: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    margin: auto;
    position: relative;
    width: 60%;
}

.alert {
    border-radius: .25rem;
    border: 1px solid transparent;
    margin-bottom: 1rem;
    padding: .75rem 1.25rem;
    position: relative;
}

.alert-danger {
    background-color: #f8d7da;
    border-color: #f5c6cb;
    color: #721c24;
}