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

:root {
    --primary-color: #2196F3;
    --success-color: #4CAF50;
    --warning-color: #FFC107;
    --danger-color: #F44336;
    --purple-color: #9C27B0;
    --white: #ffffff;
    --light-gray: #f5f5f5;
    --gray: #9e9e9e;
    --dark-gray: #424242;
    --black: #212121;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--black);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

body.dark-mode {
    --white: #1e1e1e;
    --light-gray: #2d2d2d;
    --black: #ffffff;
    --dark-gray: #f0f0f0;
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
}

/* Navigation */
.navbar {
    background: linear-gradient(135deg, var(--primary-color), var(--purple-color));
    box-shadow: var(--shadow);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    color: var(--white);
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-brand i {
    margin-right: 0.5rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--white);
    text-decoration: none;
    padding: 0.5rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
    opacity: 0.8;
}

.nav-link:hover,
.nav-link.active {
    opacity: 1;
    background: rgba(255, 255, 255, 0.1);
}

.nav-link i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-link span {
    font-size: 0.8rem;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--white);
    margin: 3px 0;
    transition: var(--transition);
}

/* Main Content */
.main-content {
    margin-top: 80px;
    min-height: calc(100vh - 160px);
}

.section {
    display: none;
    padding: 2rem 0;
}

.section.active {
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h1 {
    font-size: 2.5rem;
    color: var(--white);
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.section-header p {
    color: var(--white);
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.dashboard-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
}

.dashboard-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: linear-gradient(135deg, var(--light-gray), #e0e0e0);
}

.card-header h3 {
    display: flex;
    align-items: center;
    color: var(--black);
    font-size: 1.1rem;
}

.card-header i {
    margin-right: 0.5rem;
}

.badge {
    background: var(--primary-color);
    color: var(--white);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
}

.card-content {
    padding: 1.5rem;
}

.empty-state {
    text-align: center;
    color: var(--gray);
    font-style: italic;
}

/* Critical Stock Styling */
.critical-stock .badge {
    background: var(--danger-color);
}

.critical-stock .card-header {
    background: linear-gradient(135deg, #ffebee, #ffcdd2);
}

/* Good Stock Styling */
.good-stock .badge {
    background: var(--success-color);
}

.good-stock .card-header {
    background: linear-gradient(135deg, #e8f5e8, #c8e6c9);
}

/* Recent Entries Styling */
.recent-entries .card-header {
    background: linear-gradient(135deg, #e3f2fd, #bbdefb);
}

/* Quick Actions */
.quick-actions .card-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    gap: 0.5rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #1976d2);
    color: var(--white);
}

.btn-secondary {
    background: linear-gradient(135deg, var(--gray), #757575);
    color: var(--white);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #388e3c);
    color: var(--white);
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning-color), #f57c00);
    color: var(--black);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #d32f2f);
    color: var(--white);
}

.btn-info {
    background: linear-gradient(135deg, #17a2b8, #138496);
    color: var(--white);
}

/* Forms */
.form-container {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.product-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--black);
}

.form-group input,
.form-group select {
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 1rem;
}

/* Filters */
.filters {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.filter-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.filter-group select {
    padding: 0.5rem;
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    background: var(--white);
}

.search-group {
    position: relative;
}

.search-group input {
    padding: 0.5rem 2.5rem 0.5rem 1rem;
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    width: 250px;
}

.search-group i {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gray);
}

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

.product-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
    position: relative;
}

.product-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}

.product-card.critical {
    border-left: 5px solid var(--danger-color);
}

.product-card.warning {
    border-left: 5px solid var(--warning-color);
}

.product-card.ok {
    border-left: 5px solid var(--success-color);
}

.product-header {
    padding: 1rem;
    background: linear-gradient(135deg, var(--light-gray), #f0f0f0);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.product-name {
    font-weight: bold;
    font-size: 1.1rem;
}

.product-category {
    background: var(--primary-color);
    color: var(--white);
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 0.8rem;
}

.product-body {
    padding: 1rem;
}

.product-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.info-item {
    display: flex;
    flex-direction: column;
}

.info-label {
    font-size: 0.8rem;
    color: var(--gray);
    margin-bottom: 0.25rem;
}

.info-value {
    font-weight: 500;
}

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

/* List Actions */
.list-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Shopping List */
.shopping-list-container {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.shopping-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid #e0e0e0;
}

.shopping-item:last-child {
    border-bottom: none;
}

.item-info {
    display: flex;
    flex-direction: column;
}

.item-name {
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.item-details {
    font-size: 0.9rem;
    color: var(--gray);
}

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

/* History */
.history-filters {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.history-filters select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--white);
    border-radius: var(--border-radius);
    background: var(--white);
    font-size: 1rem;
}

.history-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    align-items: start;
}

.chart-container {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 2rem;
}

.history-stats {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.stat-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    text-align: center;
}

.stat-card h3 {
    font-size: 0.9rem;
    color: var(--gray);
    margin-bottom: 0.5rem;
}

.stat-card span {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

/* Settings */
.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.settings-card {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 2rem;
}

.settings-card h3 {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
    color: var(--black);
}

.settings-card h3 i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

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

.setting-item:last-child {
    margin-bottom: 0;
}

/* Switch Toggle */
.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: var(--transition);
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: var(--transition);
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
}

.modal-content {
    background-color: var(--white);
    margin: 5% auto;
    padding: 0;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 500px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid #e0e0e0;
}

.modal-header h3 {
    margin: 0;
}

.close {
    color: var(--gray);
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
}

.close:hover {
    color: var(--black);
}

.modal-body {
    padding: 1.5rem;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, var(--dark-gray), var(--black));
    color: var(--white);
    text-align: center;
    padding: 1rem 0;
    margin-top: 2rem;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
}

.footer a:hover {
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: linear-gradient(135deg, var(--primary-color), var(--purple-color));
        flex-direction: column;
        padding: 1rem 0;
    }

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

    .hamburger {
        display: flex;
    }

    .nav-container {
        padding: 1rem;
    }

    .section-header h1 {
        font-size: 2rem;
    }

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

    .form-row {
        grid-template-columns: 1fr;
    }

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

    .filter-group {
        justify-content: stretch;
    }

    .filter-group select {
        flex: 1;
    }

    .search-group input {
        width: 100%;
    }

    .history-content {
        grid-template-columns: 1fr;
    }

    .history-stats {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        display: grid;
    }

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

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

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

    .container {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .stock-grid {
        grid-template-columns: 1fr;
    }

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

    .modal-content {
        margin: 10% auto;
        width: 95%;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

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

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

.mb-1 {
    margin-bottom: 1rem;
}

.mb-2 {
    margin-bottom: 2rem;
}

.mt-1 {
    margin-top: 1rem;
}

.mt-2 {
    margin-top: 2rem;
}

.hidden {
    display: none;
}

.fade-in {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Status Colors */
.status-ok {
    color: var(--success-color);
}

.status-warning {
    color: var(--warning-color);
}

.status-critical {
    color: var(--danger-color);
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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