:root {
    --bs-primary: #0a2540; /* note_2.html から持ってきた元の青色 */
    --bs-primary-rgb: 10, 37, 64;
    --bs-body-bg: #f0f2f5;
}
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}
.login-card {
    max-width: 450px;
    width: 100%;
    border: none;
    box-shadow: 0 0.5rem 1.5rem rgba(0,0,0,0.1);
}
.form-control:focus, .btn-primary:focus {
    box-shadow: 0 0 0 0.25rem rgba(var(--bs-primary-rgb), 0.25);
    border-color: rgba(var(--bs-primary-rgb), 0.5);
}
.btn-primary {
    background-color: var(--bs-primary);
    border-color: var(--bs-primary);
}