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

:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --info-color: #16a085;
    --light-bg: #ecf0f1;
    --dark-text: #2c3e50;
    --border-color: #ddd;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--dark-text);
    background: #f5f7fa;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navbar */
.navbar {
    background: linear-gradient(135deg, var(--primary-color), var(--info-color));
    color: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    max-width: 1400px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-brand i {
    font-size: 1.8rem;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 0.5rem;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.25rem;
    border-radius: 8px;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-menu a:hover,
.nav-menu a.active {
    background: rgba(255, 255, 255, 0.2);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 2rem 1rem;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

/* Page Header */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.page-header h1 {
    font-size: 2rem;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.page-header p {
    color: #7f8c8d;
    margin-top: 0.25rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.3s;
    font-weight: 500;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: #229954;
    transform: translateY(-2px);
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

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

.btn-secondary {
    background: #95a5a6;
    color: white;
}

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

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    background: #138d75;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-xs {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: transform 0.3s;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: white;
}

.stat-card.blue .stat-icon {
    background: linear-gradient(135deg, var(--primary-color), #5dade2);
}

.stat-card.green .stat-icon {
    background: linear-gradient(135deg, var(--success-color), #52be80);
}

.stat-card.orange .stat-icon {
    background: linear-gradient(135deg, var(--warning-color), #f8c471);
}

.stat-card.purple .stat-icon {
    background: linear-gradient(135deg, #9b59b6, #bb8fce);
}

.stat-details h3 {
    font-size: 1.75rem;
    color: var(--secondary-color);
    margin-bottom: 0.25rem;
}

.stat-details p {
    color: #7f8c8d;
    font-size: 0.9rem;
}

/* Quick Actions */
.quick-actions {
    margin-bottom: 2rem;
}

.quick-actions h2 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.action-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Cards */
.card {
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    overflow: hidden;
}

.card-header {
    padding: 1.5rem;
    background: linear-gradient(to right, #f8f9fa, white);
    border-bottom: 2px solid var(--light-bg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.card-header h2 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--secondary-color);
    font-size: 1.3rem;
}

.card-body {
    padding: 1.5rem;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

/* Table */
.table-responsive {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: var(--light-bg);
    font-weight: 600;
    color: var(--secondary-color);
}

.table tr:hover {
    background: #f8f9fa;
}

.text-success {
    color: var(--success-color);
}

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

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: #95a5a6;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state p {
    font-size: 1.1rem;
}

/* Badge */
.badge {
    display: inline-block;
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.badge-primary {
    background: var(--primary-color);
    color: white;
}

.badge-warning {
    background: var(--warning-color);
    color: white;
}

.badge-danger {
    background: var(--danger-color);
    color: white;
}

.stock-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
}

.stock-badge.warning {
    background: #fff3cd;
    color: #856404;
}

.stock-badge.danger {
    background: #f8d7da;
    color: #721c24;
}

/* Alert List */
.alert-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.alert-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: #fff3cd;
    border-left: 4px solid var(--warning-color);
    border-radius: 6px;
}

.alert-info {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

/* Link */
.link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.link:hover {
    text-decoration: underline;
}

/* Products Grid */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.product-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.product-image {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--light-bg);
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.product-image .stock-badge {
    position: absolute;
    top: 10px;
    right: 10px;
}

.product-info {
    padding: 1.25rem;
}

.product-info h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.product-description {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.product-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.product-meta .price {
    font-size: 1.25rem;
    font-weight: bold;
    color: var(--success-color);
}

.product-meta .stock {
    color: #7f8c8d;
    font-size: 0.9rem;
}

.product-actions {
    display: flex;
    gap: 0.5rem;
}

.product-actions .btn {
    flex: 1;
}

/* Form */
.form {
    max-width: 800px;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: #7f8c8d;
    font-size: 0.85rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Alert */
.alert {
    padding: 1rem 1.25rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert i {
    font-size: 1.2rem;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border-left: 4px solid var(--success-color);
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border-left: 4px solid var(--danger-color);
}

/* Sales Grid */
.sales-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

/* Products List */
.products-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    max-height: 600px;
    overflow-y: auto;
}

.product-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.3s;
}

.product-item:hover {
    border-color: var(--primary-color);
    background: #f8f9fa;
}

.product-item-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.product-item-info img {
    width: 60px;
    height: 60px;
    object-fit: cover;
    border-radius: 8px;
}

.product-item-meta {
    display: flex;
    gap: 1rem;
    margin-top: 0.25rem;
}

.stock-info {
    color: #7f8c8d;
    font-size: 0.85rem;
}

/* Search Input */
.search-input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Cart */
.cart-items {
    max-height: 400px;
    overflow-y: auto;
    margin-bottom: 1.5rem;
}

.cart-item {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    margin-bottom: 0.75rem;
}

.cart-item-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.cart-item-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.quantity-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--light-bg);
    padding: 0.25rem;
    border-radius: 8px;
}

.quantity {
    min-width: 30px;
    text-align: center;
    font-weight: 600;
}

.cart-item-total {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--success-color);
    text-align: right;
}

/* Cart Summary */
.cart-summary {
    background: var(--light-bg);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
}

.summary-row.total {
    border-top: 2px solid var(--border-color);
    margin-top: 0.5rem;
    padding-top: 1rem;
    font-size: 1.2rem;
}

/* Reports Grid */
.reports-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

/* Filter Form */
.filter-form {
    display: flex;
    gap: 1rem;
    align-items: end;
    flex-wrap: wrap;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.filter-group label {
    font-weight: 600;
    color: var(--secondary-color);
}

.filter-group input,
.filter-group select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
}

/* Top Products List */
.top-products-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.top-product-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--light-bg);
    border-radius: 8px;
}

.rank {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    min-width: 40px;
}

.product-details {
    flex: 1;
}

.product-stats {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
    color: #7f8c8d;
    font-size: 0.9rem;
}

/* Payment Stats */
.payment-stats-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.payment-stat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--light-bg);
    border-radius: 8px;
}

.payment-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.payment-info i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.payment-count {
    display: block;
    color: #7f8c8d;
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

/* Invoice */
.invoice-container {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.invoice-header {
    display: flex;
    justify-content: space-between;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 1.5rem;
}

.invoice-header h2 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.invoice-header p {
    color: #7f8c8d;
}

.invoice-customer {
    background: var(--light-bg);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.invoice-customer h3 {
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.invoice-customer p {
    margin-bottom: 0.5rem;
}

.invoice-items {
    margin-bottom: 2rem;
}

.invoice-footer {
    text-align: center;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
    color: #7f8c8d;
}

/* Footer */
.footer {
    background: var(--secondary-color);
    color: white;
    text-align: center;
    padding: 1.5rem;
    margin-top: auto;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--secondary-color);
        flex-direction: column;
        padding: 1rem;
    }

    .nav-menu.active {
        display: flex;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .page-header h1 {
        font-size: 1.5rem;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .sales-grid {
        grid-template-columns: 1fr;
    }

    .products-grid {
        grid-template-columns: 1fr;
    }

    .reports-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
        width: 100%;
    }

    .action-buttons .btn {
        width: 100%;
        justify-content: center;
    }

    .form-actions {
        flex-direction: column;
    }

    .form-actions .btn {
        width: 100%;
        justify-content: center;
    }

    .invoice-header {
        flex-direction: column;
        gap: 1rem;
    }

    .filter-form {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-group {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .product-item-meta {
        flex-direction: column;
        gap: 0.25rem;
    }

    .product-stats {
        flex-direction: column;
        gap: 0.25rem;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .footer,
    .page-header,
    .no-print {
        display: none !important;
    }

    .main-content {
        padding: 0;
    }

    .invoice-container {
        box-shadow: none;
    }
}