:root {
    --primary-color: #0d6efd;
    --secondary-color: #6c757d;
    --success-color: #198754;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #0dcaf0;
    --light-color: #f8f9fa;
    --dark-color: #212529;
}

body {
    background-color: #f8f9fa;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.navbar-brand {
    font-weight: 600;
}

.stat-card {
    transition: transform 0.2s ease-in-out;
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.card {
    border: none;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
}

.card-header {
    background-color: #fff;
    border-bottom: 1px solid #dee2e6;
    font-weight: 600;
}

.table-hover tbody tr:hover {
    background-color: rgba(13, 110, 253, 0.05);
    cursor: pointer;
}

.table-hover tbody tr.selected {
    background-color: rgba(13, 110, 253, 0.1);
}

.list-group-item:hover {
    background-color: rgba(13, 110, 253, 0.05);
    cursor: pointer;
}

.list-group-item.selected {
    background-color: var(--primary-color);
    color: white;
}

.customer-card, .unit-card {
    border-left: 4px solid var(--primary-color);
}

.due-amount-positive {
    color: var(--danger-color);
    font-weight: 600;
}

.due-amount-zero {
    color: var(--success-color);
    font-weight: 600;
}

.due-amount-null {
    color: var(--info-color);
    font-weight: 600;
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.25);
}

.btn {
    font-weight: 500;
    transition: all 0.2s ease-in-out;
}

.btn:hover {
    transform: translateY(-1px);
}

.nav-tabs .nav-link {
    border: none;
    color: var(--secondary-color);
}

.nav-tabs .nav-link.active {
    background-color: var(--primary-color);
    color: white;
    border: none;
}

.nav-tabs .nav-link.disabled {
    opacity: 0.5;
}

.product-row {
    animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.invoice-preview {
    border: 1px solid #dee2e6;
    border-radius: 0.5rem;
    padding: 1.5rem;
    background-color: white;
}

.invoice-header {
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
}

.invoice-total {
    background-color: var(--light-color);
    padding: 1rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--success-color);
}

.customer-search-item {
    transition: background-color 0.2s ease;
}

.customer-search-item:hover {
    background-color: var(--light-color);
}

.unit-item {
    transition: all 0.2s ease;
    cursor: pointer;
}

.unit-item:hover {
    background-color: var(--light-color);
    border-color: var(--primary-color) !important;
}

.unit-item.selected {
    background-color: rgba(13, 110, 253, 0.1);
    border-color: var(--primary-color) !important;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

@media (max-width: 768px) {
    .container-fluid {
        padding-left: 15px;
        padding-right: 15px;
    }
    
    .card {
        margin-bottom: 1rem;
    }
    
    .table-responsive {
        font-size: 0.9rem;
    }
    
    .btn-group .btn {
        padding: 0.375rem 0.5rem;
        font-size: 0.875rem;
    }
}

.text-trashed {
    color: var(--danger-color) !important;
    text-decoration: line-through;
}

.alert-dismissible .btn-close {
    padding: 0.75rem 1rem;
}

.invoice-number {
    font-size: 1.2em;
    font-weight: 600;
    color: var(--primary-color);
}

/* Authentication Styles */
.btn-check:checked + .btn-outline-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.login-method-toggle {
    border-radius: 0.5rem;
    overflow: hidden;
}

#recaptcha-container {
    display: flex;
    justify-content: center;
}

#otpCode {
    font-size: 1.2rem;
    letter-spacing: 0.2rem;
    font-weight: 600;
}

.phone-input {
    font-family: 'Courier New', monospace;
}

/* Modal improvements */
.modal-content {
    border: none;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.modal-header {
    border-bottom: 1px solid #dee2e6;
    background-color: #f8f9fa;
}

/* Form validation improvements */
.was-validated .form-control:valid {
    border-color: var(--success-color);
}

.was-validated .form-control:invalid {
    border-color: var(--danger-color);
}

.purchase-history-modal .table thead.sticky-top {
    position: sticky;
    top: 0;
    z-index: 10;
}

.purchase-history-modal .table-hover tbody tr:hover {
    background-color: rgba(13, 110, 253, 0.05);
}

.table-success {
    background-color: rgba(25, 135, 84, 0.1) !important;
}

.table-warning {
    background-color: rgba(255, 193, 7, 0.15) !important;
}

.table-danger {
    background-color: rgba(220, 53, 69, 0.1) !important;
}

.table-success:hover {
    background-color: rgba(25, 135, 84, 0.2) !important;
}

.table-warning:hover {
    background-color: rgba(255, 193, 7, 0.25) !important;
}

.table-danger:hover {
    background-color: rgba(220, 53, 69, 0.2) !important;
}