/* ===== CSS Reset & Variables ===== */
:root {
    /* Primary Colors */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;
    
    /* Secondary Colors */
    --secondary-50: #f8fafc;
    --secondary-100: #f1f5f9;
    --secondary-200: #e2e8f0;
    --secondary-300: #cbd5e1;
    --secondary-400: #94a3b8;
    --secondary-500: #64748b;
    --secondary-600: #475569;
    --secondary-700: #334155;
    --secondary-800: #1e293b;
    --secondary-900: #0f172a;
    
    /* Semantic Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #1e293b;
    --bg-overlay: rgba(0, 0, 0, 0.5);
    
    /* Text Colors */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-tertiary: #94a3b8;
    --text-light: #cbd5e1;
    --text-on-dark: #ffffff;
    
    /* Border & Shadow */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-dark: #94a3b8;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-heading: 'Poppins', system-ui, -apple-system, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
    
    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
    --z-popover: 500;
    --z-tooltip: 600;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--primary-100) 0%, var(--bg-secondary) 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

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

.container {
    width: 100%;
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

h4 {
    font-size: 1.25rem;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

/* ===== Header ===== */
.app-header {
    background: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-800) 100%);
    color: var(--text-on-dark);
    padding: var(--spacing-xl) 0;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
}

.app-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--success), var(--info), var(--warning));
}

.header-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.brand {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
}

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

.logo i {
    font-size: 3rem;
    color: var(--primary-200);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.logo h1 {
    font-size: 2.5rem;
    color: var(--text-on-dark);
    letter-spacing: -0.5px;
}

.logo span {
    color: var(--primary-200);
}

.tagline {
    font-size: 1.125rem;
    color: var(--primary-100);
    max-width: 600px;
    margin: 0 auto;
    opacity: 0.9;
}

/* ===== Navigation ===== */
.app-nav {
    background: var(--bg-primary);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

.nav-content {
    padding: var(--spacing-md) 0;
}

.nav-tabs {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.nav-tab {
    flex: 1;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.nav-tab:hover {
    background: var(--bg-tertiary);
    color: var(--primary-600);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav-tab.active {
    background: var(--primary-600);
    color: var(--text-on-dark);
    border-color: var(--primary-600);
    box-shadow: var(--shadow-lg);
}

.nav-tab.active:hover {
    background: var(--primary-700);
}

.nav-tab i {
    font-size: 1.5rem;
}

.tab-indicator {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-400);
    transform: scaleX(0);
    transition: transform var(--transition-normal);
}

.nav-tab.active .tab-indicator {
    transform: scaleX(1);
    background: var(--primary-200);
}

.nav-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--primary-50);
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--info);
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.nav-info i {
    color: var(--info);
    font-size: 1.25rem;
}

/* ===== Main Content ===== */
.app-main {
    flex: 1;
    padding: var(--spacing-xl) 0;
}

.content-section {
    display: none;
    animation: fadeIn var(--transition-slow);
}

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

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

.section-header {
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--border-light);
}

.section-header h2 {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.section-header h2 i {
    color: var(--primary-600);
    background: var(--primary-50);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 800px;
}

/* ===== Card Styles ===== */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.card-header {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

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

.card-title i {
    color: var(--primary-600);
    font-size: 1.5rem;
}

.card-title h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.card-footer {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-light);
}

/* ===== Image Picker Section ===== */
.image-picker-grid {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

@media (max-width: 1200px) {
    .image-picker-grid {
        grid-template-columns: 1fr;
    }
}

/* Image Container */
.image-container {
    position: relative;
    overflow: hidden;
    background: var(--bg-dark);
    border-radius: var(--radius-md);
}

.image-wrapper {
    position: relative;
    width: 100%;
    height: 500px;
    cursor: crosshair;
    overflow: hidden;
}

#sampleImage {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    transition: transform 0.2s ease;
}

/* Zoom Viewer */
.zoom-viewer {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid var(--bg-primary);
    box-shadow: var(--shadow-xl);
    z-index: var(--z-popover);
    pointer-events: none;
    opacity: 0;
    transform: scale(0.8);
    transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.zoom-viewer.active {
    opacity: 1;
    transform: scale(1);
}

.zoom-grid {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.1) 1px, transparent 1px);
    background-size: 20px 20px;
}

.crosshair {
    position: absolute;
    background: var(--bg-primary);
}

.crosshair.horizontal {
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    transform: translateY(-50%);
}

.crosshair.vertical {
    left: 50%;
    top: 0;
    bottom: 0;
    width: 1px;
    transform: translateX(-50%);
}

.zoom-pixel-info {
    position: absolute;
    bottom: -40px;
    left: 0;
    right: 0;
    background: var(--bg-dark);
    color: var(--text-on-dark);
    padding: var(--spacing-sm);
    font-size: 0.875rem;
    font-family: 'Monaco', 'Consolas', monospace;
    text-align: center;
    border-radius: var(--radius-sm);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.zoom-viewer.active .zoom-pixel-info {
    opacity: 1;
}

/* Color Cursor */
.color-cursor {
    position: absolute;
    width: 40px;
    height: 40px;
    border: 3px solid var(--bg-primary);
    border-radius: 50%;
    pointer-events: none;
    transform: translate(-50%, -50%);
    box-shadow: 
        0 0 0 2px var(--bg-dark),
        0 0 20px rgba(0, 0, 0, 0.5);
    z-index: var(--z-tooltip);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.color-cursor.active {
    opacity: 1;
}

.cursor-center {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 4px;
    height: 4px;
    background: var(--bg-primary);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

/* Color Tooltip */
.color-tooltip {
    position: absolute;
    background: var(--bg-dark);
    color: var(--text-on-dark);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.875rem;
    pointer-events: none;
    z-index: var(--z-tooltip);
    white-space: nowrap;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-dark);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.color-tooltip.active {
    opacity: 1;
    transform: translateY(0);
}

.color-tooltip::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 6px 6px 0;
    border-style: solid;
    border-color: var(--bg-dark) transparent transparent transparent;
}

/* Image Controls */
.image-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

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

.zoom-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--bg-tertiary);
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
}

.zoom-display {
    min-width: 80px;
    text-align: center;
    font-family: 'Monaco', 'Consolas', monospace;
    font-weight: 600;
    color: var(--text-primary);
    padding: 0 var(--spacing-md);
}

/* ===== Color Info Panel ===== */
.color-info-panel {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.color-details-card {
    height: 100%;
}

.status-badge {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--primary-600);
    color: var(--text-on-dark);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    white-space: nowrap;
}

.color-preview-large {
    height: 150px;
    background: var(--primary-500);
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--border-light);
}

.color-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 0, 0, 0.2) 0%, transparent 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-on-dark);
    gap: var(--spacing-sm);
}

.color-overlay i {
    font-size: 2rem;
    opacity: 0.8;
}

.color-details {
    padding: var(--spacing-xl);
}

.color-meta {
    margin-bottom: var(--spacing-xl);
}

.color-name-section {
    margin-bottom: var(--spacing-md);
}

.color-name-section h4 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.color-category {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: 0.875rem;
}

.color-hex-display {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
}

.color-hex-display code {
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-600);
    flex: 1;
}

.color-values {
    margin-bottom: var(--spacing-xl);
}

.value-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-light);
}

.value-row:last-child {
    border-bottom: none;
}

.value-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-weight: 600;
    color: var(--text-secondary);
    min-width: 80px;
}

.value-label i {
    color: var(--primary-600);
    width: 20px;
}

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

.value-content code {
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.95rem;
    color: var(--text-primary);
    min-width: 180px;
    text-align: right;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary-600);
    color: var(--text-on-dark);
}

.btn-primary:hover {
    background: var(--primary-700);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
    border-color: var(--border-medium);
}

.btn-success {
    background: var(--success);
    color: var(--text-on-dark);
}

.btn-success:hover {
    background: #0da271;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-danger {
    background: var(--danger);
    color: var(--text-on-dark);
}

.btn-danger:hover {
    background: #dc2626;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-block {
    width: 100%;
}

.btn-sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
}

.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-icon:hover {
    background: var(--bg-secondary);
    color: var(--primary-600);
    transform: translateY(-2px);
}

.btn-group {
    display: flex;
    gap: 1px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.btn-group .btn {
    border-radius: 0;
    border: none;
}

/* ===== Palette Section ===== */
.palette-section {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin-top: var(--spacing-xl);
}

.section-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

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

.stat-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
    font-weight: 600;
}

.stat-badge i {
    color: var(--primary-600);
}

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

/* Palette Grid */
.palette-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.palette-item {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.palette-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.color-swatch {
    height: 120px;
    cursor: pointer;
    position: relative;
    transition: transform var(--transition-normal);
}

.color-swatch:hover {
    transform: scale(1.05);
}

.color-info {
    padding: var(--spacing-lg);
}

.hex-code {
    font-family: 'Monaco', 'Consolas', monospace;
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.color-name {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Export Section */
.export-section {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--border-light);
}

.export-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.export-label {
    font-weight: 600;
    color: var(--text-primary);
}

.format-selector {
    display: flex;
    gap: 1px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.format-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background: transparent;
    border: none;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.format-btn:hover {
    background: var(--bg-secondary);
    color: var(--primary-600);
}

.format-btn.active {
    background: var(--primary-600);
    color: var(--text-on-dark);
}

.export-preview {
    background: var(--secondary-900);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    overflow: auto;
}

.export-preview pre {
    color: var(--text-light);
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.875rem;
    margin: 0;
    white-space: pre-wrap;
    line-height: 1.6;
}

/* ===== Color Picker Section ===== */
.color-picker-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-2xl);
}

@media (max-width: 1400px) {
    .color-picker-grid {
        grid-template-columns: 1fr;
    }
}

/* Color Tools Main */
.color-tools-main {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.color-preview-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    padding: var(--spacing-xl);
}

.color-large-preview {
    height: 200px;
    border-radius: var(--radius-lg);
    background: var(--primary-500);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.color-info-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-xl);
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.8));
    color: var(--text-on-dark);
}

.color-name-large {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.color-hex-large {
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 1px;
}

/* Hue Palette */
.hue-palette {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--border-light);
}

.hue-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.hue-header h4 {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.125rem;
}

.hue-header h4 i {
    color: var(--primary-600);
}

.hue-count {
    font-size: 0.875rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 20px;
}

.hue-grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    grid-template-rows: repeat(2, 1fr);
    gap: 3px;
    height: 80px;
    margin-bottom: var(--spacing-md);
}

.hue-color {
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.hue-color:hover {
    transform: scale(1.1);
    z-index: 2;
    box-shadow: 
        0 0 0 2px var(--bg-primary),
        0 0 0 4px var(--primary-600);
}

.hue-color.active {
    border: 2px solid var(--bg-primary);
    box-shadow: 0 0 0 2px var(--primary-600);
    z-index: 3;
}

/* Color Formats */
.color-formats {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--border-light);
}

.formats-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.formats-header h4 {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.125rem;
}

.formats-header h4 i {
    color: var(--primary-600);
}

.formats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

@media (max-width: 768px) {
    .formats-grid {
        grid-template-columns: 1fr;
    }
}

.format-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    border: 1px solid var(--border-light);
}

.format-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.format-header span {
    font-weight: 600;
    color: var(--text-primary);
}

.format-code {
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.95rem;
    color: var(--text-secondary);
    word-break: break-all;
}

/* Color Controls */
.color-controls-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--border-light);
}

.color-input-group {
    display: flex;
    gap: var(--spacing-md);
}

.color-input-group input {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 1rem;
    color: var(--text-primary);
    transition: border-color var(--transition-normal);
}

.color-input-group input:focus {
    outline: none;
    border-color: var(--primary-600);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* Color Sliders */
.color-sliders {
    margin: var(--spacing-2xl) 0;
}

.slider-group {
    margin-bottom: var(--spacing-xl);
}

.slider-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.slider-header label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.125rem;
}

.slider-value {
    font-family: 'Monaco', 'Consolas', monospace;
    font-weight: 700;
    color: var(--primary-600);
    min-width: 60px;
    text-align: right;
}

.slider {
    width: 100%;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    outline: none;
    -webkit-appearance: none;
    transition: background var(--transition-normal);
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--primary-600);
    cursor: pointer;
    border: 3px solid var(--bg-primary);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.slider::-webkit-slider-thumb:hover {
    background: var(--primary-700);
    transform: scale(1.1);
}

.slider-scale {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

/* Quick Colors */
.quick-colors {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border-light);
}

.quick-colors h4 {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
}

.quick-colors h4 i {
    color: var(--primary-600);
}

.quick-colors-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--spacing-md);
}

@media (max-width: 1024px) {
    .quick-colors-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 640px) {
    .quick-colors-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.quick-color {
    aspect-ratio: 1;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.quick-color:hover {
    transform: scale(1.1);
    border-color: var(--primary-600);
    box-shadow: var(--shadow-md);
}

.quick-color::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), transparent);
}

/* ===== Sidebar Tools ===== */
.color-tools-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 1px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.sidebar-tab {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    background: var(--bg-primary);
    border: none;
    border-left: 4px solid transparent;
    text-align: left;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.sidebar-tab:hover {
    background: var(--bg-secondary);
    border-left-color: var(--primary-300);
}

.sidebar-tab.active {
    background: var(--primary-50);
    border-left-color: var(--primary-600);
    color: var(--primary-700);
}

.sidebar-tab i {
    font-size: 1.25rem;
    width: 24px;
}

.sidebar-tab span {
    font-weight: 600;
    flex: 1;
}

.sidebar-content {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--border-light);
    max-height: 600px;
    overflow-y: auto;
}

.sidebar-tab-content {
    display: none;
    animation: fadeIn var(--transition-normal);
}

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

.tab-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

/* Converter */
.converter {
    margin-top: var(--spacing-lg);
}

.converter-input {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.converter-input input {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 1rem;
}

.converter-results {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
}

.result-label {
    font-weight: 600;
    color: var(--text-primary);
    min-width: 60px;
}

.result-value {
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

/* Variants Grid */
.variants-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

@media (max-width: 768px) {
    .variants-grid {
        grid-template-columns: 1fr;
    }
}

.variant-item {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    border: 1px solid var(--border-light);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.variant-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-600);
}

.variant-color {
    height: 80px;
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
    overflow: hidden;
}

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

.variant-info .hex {
    font-family: 'Monaco', 'Consolas', monospace;
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-primary);
}

.variant-info .name {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Harmony Selector */
.harmony-selector {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.harmony-btn {
    padding: var(--spacing-md);
    background: var(--bg-secondary);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.harmony-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary-300);
}

.harmony-btn.active {
    background: var(--primary-600);
    color: var(--text-on-dark);
    border-color: var(--primary-600);
}

.harmony-display {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.harmony-colors {
    display: flex;
    height: 100px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.harmony-color {
    flex: 1;
    position: relative;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.harmony-color:hover {
    transform: scaleY(1.1);
    z-index: 2;
}

/* Contrast Tester */
.contrast-tester {
    margin-top: var(--spacing-lg);
}

.contrast-preview {
    background: var(--primary-500);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
}

.preview-content {
    color: var(--text-on-dark);
    text-align: center;
    max-width: 500px;
}

.preview-content h4 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.preview-content p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 0;
}

.contrast-controls {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.color-pair {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-2xl);
}

@media (max-width: 768px) {
    .color-pair {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
}

.color-control {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.color-control label {
    font-weight: 600;
    color: var(--text-primary);
}

.color-input-combo {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
}

.color-input-combo input[type="color"] {
    width: 60px;
    height: 60px;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
}

.color-input-combo input[type="text"] {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 1rem;
}

.contrast-results {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

@media (max-width: 768px) {
    .contrast-results {
        grid-template-columns: 1fr;
    }
}

.ratio-display {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    border: 1px solid var(--border-light);
}

.ratio-value {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 700;
    color: var(--success);
    margin-bottom: var(--spacing-sm);
}

.ratio-label {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.wcag-compliance {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    border: 1px solid var(--border-light);
}

.wcag-compliance h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
}

.compliance-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-light);
}

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

.compliance-badge {
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
}

.compliance-badge.success {
    background: var(--success);
    color: var(--text-on-dark);
}

.compliance-badge.warning {
    background: var(--warning);
    color: var(--text-on-dark);
}

/* ===== Footer ===== */
.app-footer {
    background: var(--bg-dark);
    color: var(--text-on-dark);
    padding: var(--spacing-2xl) 0;
    margin-top: auto;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-2xl);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
}

.footer-brand i {
    color: var(--primary-400);
}

.footer-info {
    flex: 1;
    max-width: 600px;
}

.footer-info p {
    color: var(--text-light);
    margin-bottom: var(--spacing-lg);
}

.footer-links {
    display: flex;
    gap: var(--spacing-2xl);
}

.footer-links a {
    color: var(--text-light);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: color var(--transition-normal);
}

.footer-links a:hover {
    color: var(--primary-400);
}

/* ===== Toast Notification ===== */
.toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--success);
    color: var(--text-on-dark);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    z-index: var(--z-modal);
    transform: translateX(100%);
    opacity: 0;
    transition: all var(--transition-normal);
}

.toast.show {
    transform: translateX(0);
    opacity: 1;
}

.toast-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.toast-content i {
    font-size: 1.5rem;
}

.toast-message {
    display: flex;
    flex-direction: column;
}

.toast-message strong {
    font-size: 1rem;
    margin-bottom: 2px;
}

.toast-message span {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* ===== Modal ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: var(--z-modal);
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-overlay);
    backdrop-filter: blur(4px);
}

.modal-dialog {
    position: relative;
    width: 100%;
    max-width: 900px;
    max-height: 90vh;
    overflow: hidden;
}

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.modal-header {
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: 1.5rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all var(--transition-normal);
}

.modal-close:hover {
    background: var(--bg-tertiary);
    color: var(--danger);
}

.modal-body {
    padding: var(--spacing-xl);
    overflow-y: auto;
}

.sample-images-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.sample-image-item {
    border-radius: var(--radius-md);
    overflow: hidden;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: 2px solid transparent;
    background: var(--bg-secondary);
}

.sample-image-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-600);
}

.sample-image-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    display: block;
}

.sample-image-item div {
    padding: var(--spacing-md);
    font-size: 0.95rem;
    color: var(--text-primary);
    text-align: center;
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .image-picker-grid {
        gap: var(--spacing-lg);
    }
    
    .palette-grid {
        grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    }
}

@media (max-width: 768px) {
    .nav-tabs {
        flex-direction: column;
    }
    
    .image-wrapper {
        height: 300px;
    }
    
    .color-picker-grid {
        gap: var(--spacing-lg);
    }
    
    .formats-grid {
        grid-template-columns: 1fr;
    }
    
    .harmony-selector {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        justify-content: center;
    }
    
    .modal-dialog {
        max-width: 95vw;
    }
    
    .sample-images-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

@media (max-width: 640px) {
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.75rem;
    }
    
    .logo {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-sm);
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .section-actions {
        flex-direction: column;
        align-items: stretch;
        gap: var(--spacing-md);
    }
    
    .action-buttons {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .palette-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }
    
    .quick-colors-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

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

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

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

.hidden {
    display: none !important;
}

/* ===== Scrollbar Styling ===== */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb {
    background: var(--secondary-400);
    border-radius: 5px;
}

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