/* ============================================
   DESIGN SYSTEM & CSS VARIABLES
   ============================================ */

:root {
    /* Color Palette - Modern Dark Theme */
    --color-bg-primary: #0f0f14;
    --color-bg-secondary: #1a1a24;
    --color-bg-tertiary: #25253a;
    --color-bg-elevated: rgba(42, 42, 62, 0.8);

    --color-surface: rgba(255, 255, 255, 0.05);
    --color-surface-hover: rgba(255, 255, 255, 0.08);
    --color-surface-active: rgba(255, 255, 255, 0.12);

    --color-border: rgba(255, 255, 255, 0.1);
    --color-border-hover: rgba(255, 255, 255, 0.2);

    /* Accent Colors */
    --color-primary: hsl(260, 85%, 65%);
    --color-primary-hover: hsl(260, 85%, 72%);
    --color-primary-active: hsl(260, 85%, 58%);

    --color-secondary: hsl(200, 75%, 55%);
    --color-secondary-hover: hsl(200, 75%, 62%);

    --color-accent: hsl(340, 75%, 60%);
    --color-success: hsl(140, 65%, 55%);
    --color-warning: hsl(40, 90%, 60%);

    /* Text Colors */
    --color-text-primary: rgba(255, 255, 255, 0.95);
    --color-text-secondary: rgba(255, 255, 255, 0.65);
    --color-text-tertiary: rgba(255, 255, 255, 0.4);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(155, 135, 245, 0.3);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-medium: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout */
    --sidebar-width: 280px;
    --toolbar-height: 64px;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font-primary);
    font-size: 14px;
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   LAYOUT
   ============================================ */

.app-container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: 100%;
}

/* Top Toolbar */
.top-toolbar {
    height: var(--toolbar-height);
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-lg);
    backdrop-filter: blur(10px);
    z-index: 100;
}

.toolbar-section {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.toolbar-actions {
    gap: var(--space-sm);
}

.toolbar-divider {
    width: 1px;
    height: 24px;
    background: var(--color-border);
    margin: 0 var(--space-sm);
}

.app-title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.title-icon {
    font-size: 24px;
    filter: drop-shadow(0 0 8px rgba(155, 135, 245, 0.5));
}

/* Main Content Area */
.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Sidebars */
.sidebar {
    width: var(--sidebar-width);
    background: var(--color-bg-secondary);
    border-color: var(--color-border);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    overflow-x: hidden;
}

.sidebar-left {
    border-right: 1px solid var(--color-border);
}

.sidebar-right {
    border-left: 1px solid var(--color-border);
}

.sidebar-section {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.sidebar-section:last-child {
    flex: 1;
    border-bottom: none;
}

.section-title {
    font-family: var(--font-display);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

/* Canvas Area */
.canvas-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--color-bg-primary);
    position: relative;
    overflow: hidden;
}

.canvas-controls {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    z-index: 10;
    display: flex;
    gap: var(--space-md);
}

.zoom-controls {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--color-bg-elevated);
    backdrop-filter: blur(20px);
    padding: var(--space-sm);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
}

.zoom-level {
    min-width: 50px;
    text-align: center;
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-secondary);
}

.canvas-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-2xl);
    overflow: hidden;
}

#main-canvas {
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-sm);
}

/* Tool Grid */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
}

.tool-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: var(--font-primary);
    font-size: 12px;
    font-weight: 500;
}

.tool-btn:hover {
    background: var(--color-surface-hover);
    border-color: var(--color-border-hover);
    color: var(--color-text-primary);
    transform: translateY(-2px);
}

.tool-btn.active {
    background: linear-gradient(135deg, rgba(155, 135, 245, 0.2), rgba(86, 162, 237, 0.2));
    border-color: var(--color-primary);
    color: var(--color-primary);
    box-shadow: 0 0 0 1px var(--color-primary) inset;
}

.tool-btn svg {
    flex-shrink: 0;
}

/* Pages List */
.pages-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-top: var(--space-md);
}

.page-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.page-item:hover {
    background: var(--color-surface-hover);
    border-color: var(--color-border-hover);
}

.page-item.active {
    background: linear-gradient(135deg, rgba(155, 135, 245, 0.15), rgba(86, 162, 237, 0.15));
    border-color: var(--color-primary);
}

.page-item.dragging {
    opacity: 0.5;
    border-style: dashed;
}

.page-item.drag-over {
    border-color: var(--color-secondary);
    background: linear-gradient(135deg, rgba(86, 162, 237, 0.2), rgba(155, 135, 245, 0.2));
}

.page-drag-handle {
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: grab;
    color: var(--color-text-tertiary);
}

.page-item:hover .page-drag-handle {
    color: var(--color-text-secondary);
}

.page-thumbnail {
    width: 48px;
    height: 64px;
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.page-thumbnail canvas {
    width: 100%;
    height: 100%;
}

.page-info {
    flex: 1;
}

.page-name {
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-primary);
}

.page-size {
    font-size: 11px;
    color: var(--color-text-tertiary);
}

.page-delete {
    padding: var(--space-xs);
    background: transparent;
    border: none;
    color: var(--color-text-tertiary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.page-delete:hover {
    background: rgba(255, 100, 100, 0.2);
    color: var(--color-accent);
}

/* Properties & Layers Panels */
.properties-panel,
.layers-panel {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.property-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.property-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.layer-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.layer-item:hover {
    background: var(--color-surface-hover);
    border-color: var(--color-border-hover);
}

.layer-item.selected {
    border-color: var(--color-primary);
    background: rgba(155, 135, 245, 0.1);
}

.layer-item.dragging {
    opacity: 0.5;
    border-style: dashed;
}

.layer-item.drag-over {
    border-color: var(--color-secondary);
    background: linear-gradient(135deg, rgba(86, 162, 237, 0.2), rgba(155, 135, 245, 0.2));
}


/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-xl);
    text-align: center;
    color: var(--color-text-tertiary);
}

.empty-state svg {
    opacity: 0.3;
    margin-bottom: var(--space-md);
}

.empty-state p {
    font-size: 13px;
    line-height: 1.5;
}

/* Scrollbar Styling */
.sidebar::-webkit-scrollbar,
.pages-list::-webkit-scrollbar,
.layers-panel::-webkit-scrollbar {
    width: 8px;
}

.sidebar::-webkit-scrollbar-track,
.pages-list::-webkit-scrollbar-track,
.layers-panel::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb,
.pages-list::-webkit-scrollbar-thumb,
.layers-panel::-webkit-scrollbar-thumb {
    background: var(--color-surface-hover);
    border-radius: var(--radius-full);
}

.sidebar::-webkit-scrollbar-thumb:hover,
.pages-list::-webkit-scrollbar-thumb:hover,
.layers-panel::-webkit-scrollbar-thumb:hover {
    background: var(--color-surface-active);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.page-item,
.layer-item {
    animation: fadeIn var(--transition-medium) ease-out;
}

/* ============================================
   MASTER PAGES & SPREAD VIEW STYLES
   ============================================ */

/* Section header with buttons */
.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-md);
}

.section-header .section-title {
    margin-bottom: 0;
    flex: 1;
}

/* Master mode active state */
#toggle-master-mode-btn.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: white;
}

/* Spread view active state */
#toggle-spread-view-btn.active {
    background: var(--color-secondary);
    border-color: var(--color-secondary);
    color: white;
}

/* Master page items styling */
.master-item {
    border-color: var(--color-accent);
    background: rgba(255, 100, 140, 0.05);
}

.master-item.active {
    border-color: var(--color-accent);
    background: rgba(255, 100, 140, 0.15);
}

.master-item:hover {
    border-color: var(--color-accent);
    background: rgba(255, 100, 140, 0.1);
}