:root {
    /* Color Palette - Modern Dark Theme */
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #16213e;
    --bg-hover: #252545;

    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);

    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --border-color: #2d3748;
    --border-hover: #4a5568;

    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.3);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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

/* Header */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-actions {
    display: flex;
    gap: var(--spacing-md);
}

/* Buttons */
.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
    font-family: inherit;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

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

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
    transform: translateY(-2px);
}

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    font-size: 1rem;
}

.btn-icon:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.icon {
    font-size: 1rem;
}

/* Main Content */
.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    flex: 1;
    overflow: hidden;
}

/* Panels */
.panel {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.panel-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--bg-tertiary);
}

.panel-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
    flex: 1;
}

.panel-content {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-lg);
}

/* Custom Scrollbar */
.panel-content::-webkit-scrollbar {
    width: 8px;
}

.panel-content::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.panel-content::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-sm);
}

.panel-content::-webkit-scrollbar-thumb:hover {
    background: var(--border-hover);
}

/* Tree View */
.tree-view {
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
}

.tree-node {
    margin-left: var(--spacing-lg);
}

.tree-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-bottom: 2px;
}

.tree-item:hover {
    background: var(--bg-hover);
}

.tree-item.selected {
    background: var(--accent-primary);
    color: white;
    box-shadow: var(--shadow-glow);
}

.tree-item.selected .tree-key,
.tree-item.selected .tree-value,
.tree-item.selected .tree-type {
    color: white !important;
}

.tree-toggle {
    width: 20px;
    height: 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-right: var(--spacing-xs);
    cursor: pointer;
    user-select: none;
    transition: transform var(--transition-fast);
}

.tree-toggle.collapsed {
    transform: rotate(-90deg);
}

.tree-key {
    font-weight: 600;
    color: var(--accent-secondary);
}

.tree-value {
    color: var(--text-secondary);
    margin-left: var(--spacing-sm);
}

.tree-value.string {
    color: #10b981;
}

.tree-value.number {
    color: #f59e0b;
}

.tree-value.boolean {
    color: #3b82f6;
}

.tree-value.null {
    color: var(--text-muted);
}

/* Editor Section */
.editor-section {
    margin-bottom: var(--spacing-lg);
}

.label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    padding: 0 var(--spacing-md);
}

.input,
.select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-family: inherit;
    transition: all var(--transition-fast);
}

.input:focus,
.select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.input:disabled,
.select:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.label-hint {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--text-muted);
    margin-left: var(--spacing-xs);
}

.value-input-group {
    display: flex;
    gap: var(--spacing-sm);
}

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

.toggle-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    user-select: none;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.toggle-container:hover {
    color: var(--text-primary);
}

.toggle-container input[type="checkbox"] {
    appearance: none;
    width: 32px;
    height: 18px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    position: relative;
    cursor: pointer;
    transition: all var(--transition-base);
}

.toggle-container input[type="checkbox"]:checked {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
}

.toggle-container input[type="checkbox"]::before {
    content: "";
    position: absolute;
    width: 12px;
    height: 12px;
    background: var(--text-secondary);
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: all var(--transition-base);
}

.toggle-container input[type="checkbox"]:checked::before {
    left: 16px;
    background: white;
}

.toggle-label {
    font-weight: 500;
}

.template-library-controls {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.template-library-controls .select {
    min-width: 0;
}

.template-controls {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.template-list {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    min-height: 60px;
    max-height: 150px;
    overflow-y: auto;
}

.template-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-xs);
    transition: all var(--transition-fast);
}

.template-item:hover {
    border-color: var(--border-hover);
}

.template-item-name {
    font-family: 'Courier New', monospace;
    color: var(--accent-secondary);
    font-weight: 600;
}

.template-item-remove {
    background: transparent;
    border: none;
    color: var(--danger);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    font-size: 0.875rem;
}

.template-item-remove:hover {
    background: var(--danger);
    color: white;
}

.flex-1 {
    flex: 1;
}

.select {
    width: auto;
    min-width: 120px;
}

.editor-actions {
    display: flex;
    gap: var(--spacing-md);
    margin: var(--spacing-xl) var(--spacing-md);
}

.current-value {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl);
    margin: var(--spacing-md) var(--spacing-md) 0 var(--spacing-md);
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    min-height: 100px;
    max-height: 300px;
    overflow-y: auto;
}

.current-value pre {
    margin: 0;
    white-space: pre-wrap;
    word-wrap: break-word;
}

/* Empty States */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    text-align: center;
    color: var(--text-muted);
    min-height: 200px;
}

.empty-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state p {
    margin-bottom: var(--spacing-xs);
}

.empty-hint {
    font-size: 0.875rem;
}

.empty-state-small {
    text-align: center;
    color: var(--text-muted);
    padding: var(--spacing-md);
}

/* Status Bar */
.status-bar {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-sm) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
}

.status-text {
    color: var(--text-secondary);
}

.file-name {
    color: var(--accent-primary);
    font-weight: 600;
}

/* Modal Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn var(--transition-fast);
}

.modal-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 600px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    overflow: hidden;
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

#pasteArea {
    resize: none;
    line-height: 1.4;
    padding: var(--spacing-md);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.tree-node {
    animation: fadeIn var(--transition-base);
}

/* Responsive */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .tree-panel {
        max-height: 40vh;
    }
}