/* CSS Variables for Theme Management */
:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --background-color: #ffffff;
    --surface-color: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --border-radius: 8px;
    --transition: all 0.2s ease-in-out;
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --background-color: #0f172a;
    --surface-color: #1e293b;
    --card-background: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #475569;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
}

.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
.header {
    background: var(--card-background);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    box-shadow: var(--shadow-sm);
}

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

.header h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
}

.theme-toggle:hover {
    background: var(--surface-color);
    color: var(--text-primary);
}

/* Navigation Tabs */
.nav-tabs {
    background: var(--card-background);
    border-bottom: 1px solid var(--border-color);
    padding: 0 1rem;
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    overflow-x: auto;
}

.nav-tab {
    background: none;
    border: none;
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    border-bottom: 2px solid transparent;
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.nav-tab:hover {
    color: var(--text-primary);
    background: var(--surface-color);
}

.nav-tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

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

.card {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.income-card .card-icon {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.expense-card .card-icon {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.balance-card .card-icon {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
}

.card-content h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.amount {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Quick Actions */
.quick-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.action-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.action-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.income-btn:hover {
    background: #059669;
}

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

.expense-btn:hover {
    background: #dc2626;
}

/* Recent Transactions */
.recent-transactions {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.recent-transactions h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.transactions-preview {
    max-height: 300px;
    overflow-y: auto;
}

.no-data {
    text-align: center;
    color: var(--text-secondary);
    padding: 2rem;
    font-style: italic;
}

/* Transactions Page */
.transactions-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.transactions-header h2 {
    color: var(--text-primary);
    font-weight: 700;
}

.transactions-controls {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    flex-wrap: wrap;
}

.filter-select {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.875rem;
}

.export-btn, .import-btn {
    background: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.export-btn:hover, .import-btn:hover {
    background: #475569;
}

/* Transactions Table */
.transactions-table-container {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

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

.transactions-table th {
    background: var(--surface-color);
    color: var(--text-primary);
    font-weight: 600;
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
}

.transactions-table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

.transactions-table tr:hover {
    background: var(--surface-color);
}

.transaction-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
}

.transaction-info {
    flex: 1;
}

.transaction-description {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.transaction-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.transaction-amount {
    font-weight: 700;
    font-size: 0.875rem;
}

.transaction-amount.income {
    color: var(--success-color);
}

.transaction-amount.expense {
    color: var(--danger-color);
}

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

.edit-btn, .delete-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.75rem;
}

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

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

.no-data-row td {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
    padding: 2rem;
}

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

.chart-container {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.chart-container h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-weight: 600;
    text-align: center;
}

.chart-container canvas {
    max-height: 300px;
}

/* Settings */
.settings-container {
    max-width: 600px;
}

.setting-group {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.setting-group h3 {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 1rem;
}

.setting-description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

.danger-btn {
    background: var(--danger-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.danger-btn:hover {
    background: #dc2626;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    backdrop-filter: blur(4px);
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal-content {
    background: var(--card-background);
    border-radius: var(--border-radius);
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

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

.modal-header h3 {
    color: var(--text-primary);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 4px;
    transition: var(--transition);
}

.close-btn:hover {
    background: var(--surface-color);
    color: var(--text-primary);
}

.modal-form {
    padding: 1.5rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.875rem;
}

.form-group input,
.form-group select {
    width: 100%;
    background: var(--background-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.75rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
    font-size: 0.875rem;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.error-message {
    color: var(--danger-color);
    font-size: 0.75rem;
    margin-top: 0.25rem;
    display: none;
}

.error-message.show {
    display: block;
}

.form-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: flex-end;
    margin-top: 2rem;
}

.cancel-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.cancel-btn:hover {
    background: var(--surface-color);
    color: var(--text-primary);
}

.submit-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.submit-btn:hover {
    background: var(--primary-hover);
}

.submit-btn:disabled {
    background: var(--text-secondary);
    cursor: not-allowed;
}

/* Notification */
.notification {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1001;
    transform: translateX(100%);
    transition: transform 0.3s ease-in-out;
}

.notification.show {
    transform: translateX(0);
}

.notification-content {
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1rem 1.5rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 300px;
}

.notification.success .notification-content {
    border-left: 4px solid var(--success-color);
}

.notification.error .notification-content {
    border-left: 4px solid var(--danger-color);
}

.notification.warning .notification-content {
    border-left: 4px solid var(--warning-color);
}

.notification-icon {
    font-size: 1.25rem;
}

.notification.success .notification-icon {
    color: var(--success-color);
}

.notification.error .notification-icon {
    color: var(--danger-color);
}

.notification.warning .notification-icon {
    color: var(--warning-color);
}

.notification-message {
    color: var(--text-primary);
    font-weight: 500;
}

/* Category Badges */
.category-badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: capitalize;
}

.category-badge.income {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.category-badge.food {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.category-badge.transport {
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
}

.category-badge.books {
    background: rgba(139, 92, 246, 0.1);
    color: #8b5cf6;
}

.category-badge.entertainment {
    background: rgba(236, 72, 153, 0.1);
    color: #ec4899;
}

.category-badge.others {
    background: rgba(100, 116, 139, 0.1);
    color: var(--secondary-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        padding: 0 1rem;
    }
    
    .header h1 {
        font-size: 1.25rem;
    }
    
    .nav-tabs {
        padding: 0;
    }
    
    .nav-tab {
        padding: 0.75rem 1rem;
        font-size: 0.875rem;
    }
    
    .main-content {
        padding: 1rem;
    }
    
    .overview-cards {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .quick-actions {
        flex-direction: column;
    }
    
    .action-btn {
        width: 100%;
        justify-content: center;
    }
    
    .transactions-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .transactions-controls {
        justify-content: space-between;
    }
    
    .analytics-container {
        grid-template-columns: 1fr;
    }
    
    .chart-container {
        padding: 1rem;
    }
    
    .modal-content {
        margin: 1rem;
        max-height: calc(100vh - 2rem);
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .notification {
        top: auto;
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
    }
    
    .notification-content {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .transactions-table-container {
        overflow-x: auto;
    }
    
    .transactions-table {
        min-width: 600px;
    }
    
    .card {
        padding: 1rem;
    }
    
    .card-content h3 {
        font-size: 0.75rem;
    }
    
    .amount {
        font-size: 1.25rem;
    }
}

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
button:focus-visible,
input:focus-visible,
select:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-secondary: #000000;
    }
    
    [data-theme="dark"] {
        --border-color: #ffffff;
        --text-secondary: #ffffff;
    }
}