/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f6fa;
    color: #2c3e50;
    line-height: 1.6;
}

/* Header */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: 70px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.2rem;
}

.logo span {
    font-size: 0.9rem;
    opacity: 0.9;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-info {
    padding: 0.5rem 1rem;
    background: rgba(255,255,255,0.2);
    border-radius: 20px;
    font-size: 0.9rem;
}

.logout-btn {
    background: #e74c3c;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s;
}

.logout-btn:hover {
    background: #c0392b;
}

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    top: 70px;
    left: 0;
    width: 250px;
    height: calc(100vh - 70px);
    background: white;
    box-shadow: 2px 0 10px rgba(0,0,0,0.1);
    z-index: 900;
    overflow-y: auto;
}

.nav-menu {
    list-style: none;
    padding: 1rem 0;
}

.nav-menu li {
    margin: 0.2rem 0;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 1rem 1.5rem;
    color: #2c3e50;
    text-decoration: none;
    transition: all 0.3s;
    border-left: 3px solid transparent;
}

.nav-link:hover {
    background: #f8f9fa;
    border-left-color: #667eea;
}

.nav-link.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-left-color: #4834d4;
}

.nav-icon {
    font-size: 1.2rem;
    margin-right: 0.8rem;
    width: 24px;
    text-align: center;
}

.nav-text {
    font-size: 0.95rem;
    font-weight: 500;
}

/* Main Content */
.main-content {
    margin-left: 250px;
    margin-top: 70px;
    padding: 2rem;
    min-height: calc(100vh - 70px);
}

/* Pages */
.page {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.page.active {
    display: block;
}

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

/* Page Header */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #e9ecef;
}

.page-header h2 {
    font-size: 2rem;
    color: #2c3e50;
    font-weight: 600;
}

/* Buttons */
.add-btn, .btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.add-btn:hover, .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #95a5a6;
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s;
}

.btn-secondary:hover {
    background: #7f8c8d;
}

/* Search Bar */
.search-bar {
    flex: 1;
    max-width: 400px;
    margin-left: 2rem;
}

.search-bar input {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: 25px;
    font-size: 0.95rem;
    transition: border-color 0.3s;
}

.search-bar input:focus {
    outline: none;
    border-color: #667eea;
}

/* Sales Page Specific */
.sales-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    height: calc(100vh - 200px);
}

.products-section {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow: hidden;
}

.category-filters {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.category-btn {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    color: #495057;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s;
}

.category-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.category-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-color: #667eea;
    color: white;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    max-height: calc(100vh - 350px);
    overflow-y: auto;
    padding-right: 0.5rem;
}

.product-card {
    background: white;
    border: 2px solid #e9ecef;
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    position: relative;
}

.product-card:hover {
    border-color: #667eea;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.2);
}

.product-image {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.product-name {
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

.product-price {
    font-size: 1.1rem;
    font-weight: 700;
    color: #27ae60;
    margin-bottom: 0.5rem;
}

.product-stock {
    font-size: 0.8rem;
    color: #7f8c8d;
}

.stock-low {
    color: #e74c3c;
    font-weight: 600;
}

/* Cart Section */
.cart-section {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
}

.cart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #e9ecef;
}

.cart-header h3 {
    font-size: 1.3rem;
    color: #2c3e50;
}

.clear-cart-btn {
    background: #e74c3c;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: background 0.3s;
}

.clear-cart-btn:hover {
    background: #c0392b;
}

.cart-items {
    flex: 1;
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: 1rem;
}

.cart-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.8rem;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    background: #f8f9fa;
}

.cart-item-info {
    flex: 1;
}

.cart-item-name {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.2rem;
}

.cart-item-price {
    color: #27ae60;
    font-size: 0.85rem;
}

.cart-item-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.qty-btn {
    background: #667eea;
    color: white;
    border: none;
    width: 25px;
    height: 25px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.qty-input {
    width: 50px;
    text-align: center;
    border: 1px solid #e9ecef;
    border-radius: 4px;
    padding: 0.2rem;
    font-size: 0.85rem;
}

.remove-btn {
    background: #e74c3c;
    color: white;
    border: none;
    width: 25px;
    height: 25px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 0.8rem;
}

/* Cart Summary */
.cart-summary {
    border-top: 2px solid #e9ecef;
    padding-top: 1rem;
    margin-bottom: 1rem;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.summary-row.total {
    font-weight: 700;
    font-size: 1.1rem;
    color: #2c3e50;
    border-top: 1px solid #e9ecef;
    padding-top: 0.5rem;
    margin-top: 0.5rem;
}

/* Payment Section */
.payment-section {
    border-top: 2px solid #e9ecef;
    padding-top: 1rem;
}

.customer-select, .payment-input {
    margin-bottom: 1rem;
}

.customer-select label, .payment-input label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.9rem;
}

.customer-select select, .payment-input input {
    width: 100%;
    padding: 0.6rem;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 0.9rem;
}

.payment-methods {
    margin-bottom: 1rem;
}

.payment-methods label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    font-size: 0.9rem;
}

.payment-options {
    display: flex;
    gap: 0.5rem;
}

.payment-btn {
    flex: 1;
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    color: #495057;
    padding: 0.6rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all 0.3s;
}

.payment-btn:hover {
    border-color: #667eea;
    color: #667eea;
}

.payment-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-color: #667eea;
    color: white;
}

.change-amount {
    text-align: center;
    margin-bottom: 1rem;
    font-size: 0.95rem;
    color: #27ae60;
}

.checkout-btn {
    width: 100%;
    background: linear-gradient(135deg, #27ae60 0%, #2ecc71 100%);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s;
}

.checkout-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(39, 174, 96, 0.4);
}

.checkout-btn:disabled {
    background: #95a5a6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Tables */
.table-container {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.data-table th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0.8rem;
    text-align: left;
    font-weight: 600;
    border-bottom: 2px solid #5a67d8;
}

.data-table td {
    padding: 0.8rem;
    border-bottom: 1px solid #e9ecef;
    vertical-align: middle;
}

.data-table tbody tr:hover {
    background: #f8f9fa;
}

.status-badge {
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
}

.status-active {
    background: #d4edda;
    color: #155724;
}

.status-inactive {
    background: #f8d7da;
    color: #721c24;
}

.status-low-stock {
    background: #fff3cd;
    color: #856404;
}

.action-btn {
    background: none;
    border: none;
    color: #667eea;
    cursor: pointer;
    font-size: 0.85rem;
    padding: 0.3rem 0.6rem;
    border-radius: 4px;
    transition: all 0.3s;
    margin-right: 0.3rem;
}

.action-btn:hover {
    background: #667eea;
    color: white;
}

.action-btn.delete {
    color: #e74c3c;
}

.action-btn.delete:hover {
    background: #e74c3c;
    color: white;
}

/* Reports */
.reports-container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.report-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.report-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
    border-left: 4px solid #667eea;
}

.report-card h3 {
    font-size: 1rem;
    color: #7f8c8d;
    margin-bottom: 1rem;
    font-weight: 500;
}

.report-value {
    font-size: 2rem;
    font-weight: 700;
    color: #2c3e50;
}

.sales-history {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.sales-history h3 {
    margin-bottom: 1rem;
    color: #2c3e50;
    font-size: 1.3rem;
}

/* Settings */
.settings-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.settings-section {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.settings-section h3 {
    margin-bottom: 1.5rem;
    color: #2c3e50;
    font-size: 1.3rem;
    border-bottom: 2px solid #e9ecef;
    padding-bottom: 0.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #2c3e50;
    font-size: 0.95rem;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 0.95rem;
    transition: border-color 0.3s;
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

.form-group small {
    display: block;
    margin-top: 0.3rem;
    color: #7f8c8d;
    font-size: 0.8rem;
}

.backup-actions {
    display: flex;
    gap: 1rem;
}

.backup-actions button {
    flex: 1;
    background: #3498db;
    color: white;
    border: none;
    padding: 0.8rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s;
}

.backup-actions button:hover {
    background: #2980b9;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(2px);
}

.modal-overlay.hidden {
    display: none;
}

.modal {
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px) scale(0.9);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 2px solid #e9ecef;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 12px 12px 0 0;
}

.modal-header h3 {
    font-size: 1.2rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background 0.3s;
}

.modal-close:hover {
    background: rgba(255,255,255,0.2);
}

.modal-body {
    padding: 2rem;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    padding: 1.5rem;
    border-top: 2px solid #e9ecef;
    background: #f8f9fa;
    border-radius: 0 0 12px 12px;
}

/* Loading States */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    color: #7f8c8d;
}

.loading::after {
    content: '';
    width: 20px;
    height: 20px;
    border: 2px solid #e9ecef;
    border-top: 2px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 0.5rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: #7f8c8d;
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

.text-center {
    text-align: center;
}

.text-right {
    text-align: right;
}

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}