.login-container {
    background-color: #e6e9f8;
    min-height: calc(100vh - 120px);
    display: flex;
    align-items: center;
    padding: 40px 0;
}

.login-card {
    max-width: 450px;
    width: 100%;
    margin: 0 auto;
    border: none;
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
    border-radius: 0.5rem;
}

.login-header {
    background-color: white;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    padding: 1.5rem;
    text-align: center;
    border-radius: 0.5rem 0.5rem 0 0;
}

.login-body {
    padding: 1.5rem;
}

.login-title {
    font-weight: 600;
    color: #333;
    margin-bottom: 0;
}

.form-label {
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.form-control {
    padding: 0.75rem 1rem;
    border-radius: 0.375rem;
}

.btn-login {
    padding: 0.75rem;
    font-weight: 500;
    border-radius: 0.375rem;
}

.captcha-container {
    margin-top: 1rem;
}

.captcha-container img {
    margin-bottom: 0.75rem;
    border: 1px solid #dee2e6;
    border-radius: 0.375rem;
    width: 100%;
}

.login-footer {
    text-align: center;
    padding: 1rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    background-color: #f8f9fa;
    border-bottom-left-radius: 0.5rem;
    border-bottom-right-radius: 0.5rem;
}

/* ===== BASE ALERT ===== */
.alert {
    border: none;
    border-radius: 12px;
    padding: 12px 14px;
    font-size: 0.95rem;
    line-height: 1.4;
}

/* fix flex text overflow */
.alert .flex-grow-1 {
    min-width: 0;
    word-break: break-word;
    overflow-wrap: anywhere;
}

/* ===== SYSTEM MESSAGE (warning/info) ===== */
.alert-system {
    background: #fff8e1;
    border-left: 5px solid #ffc107;
    box-shadow: 0 4px 12px rgba(255, 193, 7, 0.15);
}

.alert-system i {
    color: #ffc107;
    flex-shrink: 0;
}

/* ===== FORM ERROR (CRITICAL) ===== */
.alert-form-error {
    background: #fff1f0;
    border-left: 6px solid #dc3545;
    box-shadow: 0 6px 18px rgba(220, 53, 69, 0.2);
    font-weight: 500;
}

.alert-form-error i {
    color: #dc3545;
    flex-shrink: 0;
}

/* list trong error */
.alert-form-error ul {
    padding-left: 18px;
}

.alert-form-error li {
    margin-bottom: 4px;
}

/* ===== CLOSE BUTTON ===== */
.alert .btn-close {
    opacity: 0.6;
}

.alert .btn-close:hover {
    opacity: 1;
}

/* ===== ANIMATION ===== */
.alert {
    animation: fadeSlideIn 0.25s ease;
}

@keyframes fadeSlideIn {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}