/* 
 * Power Meter System - Base Stylesheet
 * Version: 1.0.0
 * 
 * Table of Contents:
 * 1. CSS Variables (Custom Properties)
 * 2. Reset & Base Styles
 * 3. Typography
 * 4. Layout Components
 * 5. Navigation & Sidebar
 * 6. Page Components
 * 7. Form Elements
 * 8. Buttons
 * 9. Cards & Panels
 * 10. Alerts & Notifications
 * 11. Tables
 * 12. Utilities
 * 13. Animations
 * 14. Dark Mode
 * 15. Responsive Design
 * 16. Accessibility
 */

/* ==============================================================================
   1. CSS Variables (Custom Properties)
   ============================================================================== */

   :root {
    /* Color Palette */
    --color-primary: #3b82f6;
    --color-primary-dark: #2563eb;
    --color-primary-light: #60a5fa;
    --color-primary-alpha: rgba(59, 130, 246, 0.1);
    
    --color-secondary: #6b7280;
    --color-secondary-dark: #4b5563;
    --color-secondary-light: #9ca3af;
    
    --color-success: #10b981;
    --color-success-dark: #059669;
    --color-success-light: #34d399;
    --color-success-alpha: rgba(16, 185, 129, 0.1);
    
    --color-info: #06b6d4;
    --color-info-dark: #0891b2;
    --color-info-light: #22d3ee;
    --color-info-alpha: rgba(6, 182, 212, 0.1);
    
    --color-warning: #f59e0b;
    --color-warning-dark: #d97706;
    --color-warning-light: #fbbf24;
    --color-warning-alpha: rgba(245, 158, 11, 0.1);
    
    --color-danger: #ef4444;
    --color-danger-dark: #dc2626;
    --color-danger-light: #f87171;
    --color-danger-alpha: rgba(239, 68, 68, 0.1);
    
    /* Neutral Colors */
    --color-white: #ffffff;
    --color-black: #000000;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    
    /* Theme Colors */
    --bg-body: #f3f4f6;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-surface: #ffffff;
    --bg-surface-secondary: #f9fafb;
    --bg-overlay: rgba(255, 255, 255, 0.95);
    --color-text: #1f2937;
    --color-text-secondary: #6b7280;
    --color-text-muted: #9ca3af;
    --color-text-inverse: #ffffff;
    --color-border: #e5e7eb;
    --color-border-light: #f3f4f6;
    
    /* Shadows */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;
    
    /* Z-index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
    
    /* Layout */
    --sidebar-width: 260px;
    --sidebar-collapsed-width: 70px;
    --header-height: 70px;
    --container-max-width: 1400px;
}

/* ==============================================================================
   2. Reset & Base Styles
   ============================================================================== */

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -webkit-tap-highlight-color: transparent;
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--bg-body);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==============================================================================
   3. Typography
   ============================================================================== */

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6 {
    margin-top: 0;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-text);
}

h1, .h1 { font-size: 2.5rem; }
h2, .h2 { font-size: 2rem; }
h3, .h3 { font-size: 1.75rem; }
h4, .h4 { font-size: 1.5rem; }
h5, .h5 { font-size: 1.25rem; }
h6, .h6 { font-size: 1rem; }

p {
    margin-top: 0;
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

code, kbd, pre, samp {
    font-family: var(--font-mono);
    font-size: 0.875em;
}

/* ==============================================================================
   4. Layout Components
   ============================================================================== */

/* Skip Link (Accessibility) */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    border-radius: var(--radius-md);
    z-index: var(--z-tooltip);
}

.skip-link:focus {
    top: var(--spacing-sm);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
}

.loading-overlay.show {
    display: flex;
}

.loading-content {
    background: var(--bg-surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    text-align: center;
}

.spinner-container {
    margin-bottom: var(--spacing-md);
}

.loading-text {
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* Mobile Overlay */
.mobile-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: var(--z-modal-backdrop);
}

.mobile-overlay.show {
    display: block;
}

/* ==============================================================================
   5. Navigation & Sidebar
   ============================================================================== */

.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: var(--sidebar-width);
    background-color: var(--bg-surface);
    box-shadow: var(--shadow-md);
    z-index: var(--z-fixed);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-slow);
    overflow: hidden;
}

/* Sidebar Header */
.sidebar-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.sidebar-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo-img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
    color: var(--color-primary);
}

/* Sidebar Navigation */
.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md) 0;
}

.sidebar-nav::-webkit-scrollbar {
    width: 6px;
}

.sidebar-nav::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar-nav::-webkit-scrollbar-thumb {
    background-color: var(--color-gray-300);
    border-radius: var(--radius-full);
}

.nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-item {
    margin-bottom: var(--spacing-xs);
}

.nav-link {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    color: var(--color-text-secondary);
    font-weight: 500;
    text-decoration: none;
    border-radius: 0;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--color-primary);
    background-color: var(--color-primary-alpha);
    text-decoration: none;
}

.nav-link.active {
    color: var(--color-primary);
    background-color: var(--color-primary-alpha);
}

.nav-link.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background-color: var(--color-primary);
}

.nav-link i {
    font-size: 1.25rem;
    margin-right: var(--spacing-md);
    width: 24px;
    text-align: center;
}

.nav-link span {
    flex: 1;
}

/* Dropdown Navigation */
.has-dropdown .dropdown-icon {
    margin-left: auto;
    transition: transform var(--transition-fast);
}

.has-dropdown[aria-expanded="true"] .dropdown-icon {
    transform: rotate(180deg);
}

.submenu {
    background-color: var(--bg-surface-secondary);
    margin: var(--spacing-xs) 0;
    padding: var(--spacing-xs) 0;
    border-radius: var(--radius-md);
}

.submenu .nav-link {
    padding-left: calc(var(--spacing-lg) + 24px + var(--spacing-md));
    font-size: 0.875rem;
}

.submenu .nav-link i {
    font-size: 0.5rem;
}

/* Nav Divider */
.nav-divider {
    height: 1px;
    background-color: var(--color-border);
    margin: var(--spacing-md) var(--spacing-lg);
}

/* Sidebar Footer */
.sidebar-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

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

.clock-widget {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.version-info {
    color: var(--color-text-muted);
}

/* ==============================================================================
   6. Page Components
   ============================================================================== */

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    background-color: var(--bg-body);
    transition: margin-left var(--transition-slow);
}

/* Page Header */
.page-header {
    background-color: var(--bg-surface);
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-xl);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

.page-title {
    font-size: 1.875rem;
    font-weight: 700;
    margin: 0;
    color: var(--color-text);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    background: transparent;
    border: none;
    font-size: 1.5rem;
    color: var(--color-text);
    padding: var(--spacing-sm);
    cursor: pointer;
}

/* Content Wrapper */
.content-wrapper {
    padding: 0 var(--spacing-lg) var(--spacing-xl);
}

/* ==============================================================================
   7. Form Elements
   ============================================================================== */

.form-control,
.form-select {
    display: block;
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--bg-surface);
    background-clip: padding-box;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus,
.form-select:focus {
    color: var(--color-text);
    background-color: var(--bg-surface);
    border-color: var(--color-primary);
    outline: 0;
    box-shadow: 0 0 0 3px var(--color-primary-alpha);
}

.form-control::placeholder {
    color: var(--color-text-muted);
}

.form-label {
    display: inline-block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--color-text);
}

.form-text {
    margin-top: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

/* ==============================================================================
   8. Buttons
   ============================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.5;
    text-align: center;
    text-decoration: none;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn:hover {
    text-decoration: none;
}

.btn:focus {
    outline: 0;
    box-shadow: 0 0 0 3px rgba(var(--color-primary), 0.25);
}

.btn:disabled {
    opacity: 0.65;
    cursor: not-allowed;
}

/* Button Variants */
.btn-primary {
    color: white;
    background-color: var(--color-primary);
    border-color: var(--color-primary);
}

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

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

.btn-secondary:hover {
    background-color: var(--color-secondary-dark);
    border-color: var(--color-secondary-dark);
}

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

.btn-success:hover {
    background-color: var(--color-success-dark);
    border-color: var(--color-success-dark);
}

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

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

.btn-outline-primary {
    color: var(--color-primary);
    background-color: transparent;
    border-color: var(--color-primary);
}

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

.btn-outline-secondary {
    color: var(--color-secondary);
    background-color: transparent;
    border-color: var(--color-border);
}

.btn-outline-secondary:hover {
    color: white;
    background-color: var(--color-secondary);
    border-color: var(--color-secondary);
}

/* Button Sizes */
.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.875rem;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.125rem;
}

/* ==============================================================================
   9. Cards & Panels
   ============================================================================== */

.card {
    position: relative;
    display: flex;
    flex-direction: column;
    min-width: 0;
    word-wrap: break-word;
    background-color: var(--bg-surface);
    background-clip: border-box;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-fast);
}

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

.card-header {
    padding: var(--spacing-lg);
    margin-bottom: 0;
    background-color: transparent;
    border-bottom: 1px solid var(--color-border);
}

.card-header h3,
.card-header h4,
.card-header h5 {
    margin-bottom: 0;
}

.card-body {
    flex: 1 1 auto;
    padding: var(--spacing-lg);
}

.card-footer {
    padding: var(--spacing-lg);
    background-color: var(--bg-surface-secondary);
    border-top: 1px solid var(--color-border);
    border-radius: 0 0 calc(var(--radius-lg) - 1px) calc(var(--radius-lg) - 1px);
}

/* Stat Cards */
.stat-card {
    padding: var(--spacing-lg);
    background-color: var(--bg-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

/* ==============================================================================
   10. Alerts & Notifications
   ============================================================================== */

.alert {
    position: relative;
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
}

.alert-content {
    display: flex;
    align-items: center;
}

.alert-dismissible {
    padding-right: 3rem;
}

.alert-dismissible .btn-close {
    position: absolute;
    top: 0;
    right: 0;
    padding: var(--spacing-md);
    color: inherit;
}

/* Alert Variants */
.alert-success {
    color: var(--color-success-dark);
    background-color: var(--color-success-alpha);
    border-color: var(--color-success-light);
}

.alert-info {
    color: var(--color-info-dark);
    background-color: var(--color-info-alpha);
    border-color: var(--color-info-light);
}

.alert-warning {
    color: var(--color-warning-dark);
    background-color: var(--color-warning-alpha);
    border-color: var(--color-warning-light);
}

.alert-danger {
    color: var(--color-danger-dark);
    background-color: var(--color-danger-alpha);
    border-color: var(--color-danger-light);
}

/* Toast Notifications */
.toast {
    min-width: 300px;
    background-color: var(--bg-surface);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

.toast-header {
    background-color: var(--bg-surface-secondary);
    border-bottom: 1px solid var(--color-border);
    border-radius: calc(var(--radius-md) - 1px) calc(var(--radius-md) - 1px) 0 0;
}

/* ==============================================================================
   11. Tables
   ============================================================================== */

.table {
    width: 100%;
    margin-bottom: var(--spacing-md);
    vertical-align: top;
    border-color: var(--color-border);
}

.table > :not(caption) > * > * {
    padding: var(--spacing-md);
    background-color: var(--bg-surface);
    border-bottom-width: 1px;
    box-shadow: inset 0 0 0 9999px var(--bs-table-accent-bg);
}

.table > tbody {
    vertical-align: inherit;
}

.table > thead {
    vertical-align: bottom;
}

.table-hover > tbody > tr:hover > * {
    --bs-table-accent-bg: var(--color-gray-50);
}

/* ==============================================================================
   12. Utilities
   ============================================================================== */

/* Text Utilities */
.text-primary { color: var(--color-primary) !important; }
.text-secondary { color: var(--color-secondary) !important; }
.text-success { color: var(--color-success) !important; }
.text-danger { color: var(--color-danger) !important; }
.text-warning { color: var(--color-warning) !important; }
.text-info { color: var(--color-info) !important; }
.text-muted { color: var(--color-text-muted) !important; }

/* Background Utilities */
.bg-primary { background-color: var(--color-primary) !important; }
.bg-secondary { background-color: var(--color-secondary) !important; }
.bg-success { background-color: var(--color-success) !important; }
.bg-danger { background-color: var(--color-danger) !important; }
.bg-warning { background-color: var(--color-warning) !important; }
.bg-info { background-color: var(--color-info) !important; }

/* Spacing Utilities */
.m-0 { margin: 0 !important; }
.m-1 { margin: var(--spacing-xs) !important; }
.m-2 { margin: var(--spacing-sm) !important; }
.m-3 { margin: var(--spacing-md) !important; }
.m-4 { margin: var(--spacing-lg) !important; }
.m-5 { margin: var(--spacing-xl) !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: var(--spacing-xs) !important; }
.mt-2 { margin-top: var(--spacing-sm) !important; }
.mt-3 { margin-top: var(--spacing-md) !important; }
.mt-4 { margin-top: var(--spacing-lg) !important; }
.mt-5 { margin-top: var(--spacing-xl) !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: var(--spacing-xs) !important; }
.mb-2 { margin-bottom: var(--spacing-sm) !important; }
.mb-3 { margin-bottom: var(--spacing-md) !important; }
.mb-4 { margin-bottom: var(--spacing-lg) !important; }
.mb-5 { margin-bottom: var(--spacing-xl) !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: var(--spacing-xs) !important; }
.p-2 { padding: var(--spacing-sm) !important; }
.p-3 { padding: var(--spacing-md) !important; }
.p-4 { padding: var(--spacing-lg) !important; }
.p-5 { padding: var(--spacing-xl) !important; }

/* Display Utilities */
.d-none { display: none !important; }
.d-block { display: block !important; }
.d-flex { display: flex !important; }
.d-inline-flex { display: inline-flex !important; }

/* Flex Utilities */
.flex-column { flex-direction: column !important; }
.justify-content-start { justify-content: flex-start !important; }
.justify-content-end { justify-content: flex-end !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-between { justify-content: space-between !important; }
.align-items-start { align-items: flex-start !important; }
.align-items-end { align-items: flex-end !important; }
.align-items-center { align-items: center !important; }
.flex-grow-1 { flex-grow: 1 !important; }

/* Gap Utilities */
.gap-1 { gap: var(--spacing-xs) !important; }
.gap-2 { gap: var(--spacing-sm) !important; }
.gap-3 { gap: var(--spacing-md) !important; }
.gap-4 { gap: var(--spacing-lg) !important; }
.gap-5 { gap: var(--spacing-xl) !important; }

/* ==============================================================================
   13. Animations
   ============================================================================== */

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

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.fade-in {
    animation: fadeIn var(--transition-slow) ease-out;
}

.slide-in-right {
    animation: slideInRight var(--transition-slow) ease-out;
}

.pulse {
    animation: pulse 2s infinite;
}

/* ==============================================================================
   14. Dark Mode
   ============================================================================== */

/* Dark mode color variables */
[data-theme="dark"],
body.dark-mode {
    /* Background colors */
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-body: #0d1117;
    --bg-surface: #1c2128;
    --bg-surface-secondary: #262c36;
    --bg-overlay: rgba(13, 17, 23, 0.95);
    
    /* Text colors */
    --color-text: #e6edf3;
    --color-text-secondary: #8b949e;
    --color-text-muted: #6e7681;
    --color-text-inverse: #0d1117;
    
    /* Border colors */
    --color-border: #30363d;
    --color-border-light: #21262d;
    
    /* Component colors adjusted for dark mode */
    --color-primary: #58a6ff;
    --color-primary-light: #79c0ff;
    --color-primary-alpha: rgba(88, 166, 255, 0.2);
    
    --color-success: #3fb950;
    --color-success-light: #56d364;
    --color-success-alpha: rgba(63, 185, 80, 0.2);
    
    --color-warning: #d29922;
    --color-warning-light: #e3b341;
    --color-warning-alpha: rgba(210, 153, 34, 0.2);
    
    --color-danger: #f85149;
    --color-danger-light: #ff6b6b;
    --color-danger-alpha: rgba(248, 81, 73, 0.2);
    
    --color-info: #58a6ff;
    --color-info-light: #79c0ff;
    --color-info-alpha: rgba(88, 166, 255, 0.2);
    
    /* Shadows for dark mode */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
}

/* Dark mode specific adjustments */
body.dark-mode {
    background-color: var(--bg-primary);
    color: var(--color-text);
}

/* Sidebar dark mode */
body.dark-mode .sidebar {
    background-color: var(--bg-secondary);
    border-right-color: var(--color-border);
}

body.dark-mode .sidebar-header {
    border-bottom-color: var(--color-border);
}

body.dark-mode .nav-link {
    color: var(--color-text-secondary);
}

body.dark-mode .nav-link:hover {
    color: var(--color-text);
    background-color: rgba(88, 166, 255, 0.1);
}

body.dark-mode .nav-link.active {
    color: var(--color-primary);
    background-color: rgba(88, 166, 255, 0.15);
}

body.dark-mode .nav-divider {
    background-color: var(--color-border);
}

/* Main content dark mode */
body.dark-mode .main-content {
    background-color: var(--bg-primary);
}

body.dark-mode .page-header {
    background-color: var(--bg-surface);
    border-bottom-color: var(--color-border);
}

body.dark-mode .page-title {
    color: var(--color-text);
}

/* Cards and surfaces */
body.dark-mode .card {
    background-color: var(--bg-surface);
    border-color: var(--color-border);
    color: var(--color-text);
}

body.dark-mode .card-header {
    background-color: transparent;
    border-bottom-color: var(--color-border);
}

body.dark-mode .card-footer {
    background-color: var(--bg-surface-secondary);
    border-top-color: var(--color-border);
}

/* Buttons dark mode */
body.dark-mode .btn-primary {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-text-inverse);
}

body.dark-mode .btn-primary:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary-light);
}

body.dark-mode .btn-outline-secondary {
    color: var(--color-text-secondary);
    border-color: var(--color-border);
}

body.dark-mode .btn-outline-secondary:hover {
    background-color: var(--bg-surface-secondary);
    color: var(--color-text);
    border-color: var(--color-border);
}

body.dark-mode .btn-outline-secondary.active {
    background-color: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-text-inverse);
}

/* Forms dark mode */
body.dark-mode .form-control,
body.dark-mode .form-select {
    background-color: var(--bg-surface-secondary);
    border-color: var(--color-border);
    color: var(--color-text);
}

body.dark-mode .form-control:focus,
body.dark-mode .form-select:focus {
    background-color: var(--bg-surface-secondary);
    border-color: var(--color-primary);
    color: var(--color-text);
    box-shadow: 0 0 0 0.25rem var(--color-primary-alpha);
}

/* Alerts dark mode */
body.dark-mode .alert {
    border: 1px solid var(--color-border);
}

body.dark-mode .alert-success {
    background-color: var(--color-success-alpha);
    color: var(--color-success-light);
    border-color: var(--color-success);
}

body.dark-mode .alert-warning {
    background-color: var(--color-warning-alpha);
    color: var(--color-warning-light);
    border-color: var(--color-warning);
}

body.dark-mode .alert-danger {
    background-color: var(--color-danger-alpha);
    color: var(--color-danger-light);
    border-color: var(--color-danger);
}

body.dark-mode .alert-info {
    background-color: var(--color-info-alpha);
    color: var(--color-info-light);
    border-color: var(--color-info);
}

/* Loading overlay dark mode */
body.dark-mode .loading-overlay {
    background-color: var(--bg-overlay);
}

body.dark-mode .loading-content {
    background-color: var(--bg-surface);
    color: var(--color-text);
}

/* Mobile overlay dark mode */
body.dark-mode .mobile-overlay {
    background-color: rgba(0, 0, 0, 0.7);
}

/* Clock widget dark mode */
body.dark-mode .clock-widget {
    color: var(--color-text-secondary);
}

/* Version info dark mode */
body.dark-mode .version-info {
    color: var(--color-text-muted);
}

/* Custom scrollbar for dark mode */
body.dark-mode ::-webkit-scrollbar {
    background-color: var(--bg-surface);
}

body.dark-mode ::-webkit-scrollbar-track {
    background-color: var(--bg-surface);
}

body.dark-mode ::-webkit-scrollbar-thumb {
    background-color: var(--color-border);
    border-radius: 4px;
}

body.dark-mode ::-webkit-scrollbar-thumb:hover {
    background-color: var(--color-text-muted);
}

/* Fix Bootstrap components in dark mode */
body.dark-mode .btn-close {
    filter: invert(1) grayscale(100%) brightness(200%);
}

/* Transition for smooth theme switching */
body,
.sidebar,
.main-content,
.card,
.btn,
.alert,
.badge,
.form-control,
.form-select {
    transition: background-color 0.3s ease, 
                color 0.3s ease, 
                border-color 0.3s ease,
                box-shadow 0.3s ease;
}

/* ==============================================================================
   15. Responsive Design
   ============================================================================== */

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    .container {
        max-width: 540px;
    }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }
    
    .d-lg-none { display: none !important; }
    .d-lg-block { display: block !important; }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
}

/* Extra extra large devices (larger desktops, 1400px and up) */
@media (min-width: 1400px) {
    .container {
        max-width: 1320px;
    }
}

/* Mobile Responsive Adjustments */
@media (max-width: 991.98px) {
    /* Sidebar mobile behavior */
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.show {
        transform: translateX(0);
    }
    
    /* Main content adjustment */
    .main-content {
        margin-left: 0;
    }
    
    /* Page header mobile */
    .page-header {
        position: relative;
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    /* Content wrapper mobile */
    .content-wrapper {
        padding: 0 var(--spacing-md) var(--spacing-lg);
    }
    
    /* Cards mobile */
    .card {
        margin-bottom: var(--spacing-md);
    }
    
    /* Tables mobile */
    .table-responsive {
        -webkit-overflow-scrolling: touch;
    }
}

/* ==============================================================================
   16. Accessibility
   ============================================================================== */

/* Focus styles */
:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --color-primary: #0066cc;
        --color-danger: #cc0000;
        --color-success: #008800;
        --color-warning: #cc6600;
    }
}

/* Screen reader only content */
.visually-hidden,
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-surface-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-gray-400);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-gray-500);
}

/* Print styles */
@media print {
    .sidebar,
    .page-header,
    .no-print {
        display: none !important;
    }
    
    .main-content {
        margin-left: 0 !important;
    }
    
    body {
        background: white;
        color: black;
    }
}