.auth-form
{
    width: 100%;
    max-width: 400px;
    margin: auto;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.form-group
{
    margin-bottom: 15px;
}