:root {
    /* Color Palette */
    --bg-dark: #121212;
    --bg-panel: rgba(30, 30, 35, 0.7);
    --bg-panel-hover: rgba(45, 45, 50, 0.9);
    --accent-color: #6366f1; /* Indigo */
    --accent-hover: #4f46e5;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --border-color: rgba(255, 255, 255, 0.1);
    
    /* Effects */
    --glass-blur: blur(12px);
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-glow: 0 0 15px rgba(99, 102, 241, 0.3);
    
    /* Layout */
    --toolbar-width: 60px;
    --palette-width: 250px;
    --topbar-height: 60px;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-dark);
    /* Subtle radial gradient background */
    background-image: radial-gradient(circle at 50% 0%, #2a2a35 0%, var(--bg-dark) 50%);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
}

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

/* Glassmorphism Utilities */
.glass-panel {
    background: var(--bg-panel);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-soft);
}

/* Topbar */
.topbar {
    height: var(--topbar-height);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    z-index: 10;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--accent-color);
}

.topbar-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.divider {
    width: 1px;
    height: 24px;
    background-color: var(--border-color);
    margin: 0 5px;
}

/* Buttons */
.btn {
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}

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

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

.btn-primary:hover {
    background: var(--accent-hover);
    box-shadow: var(--shadow-glow);
}

.btn-import {
    background: #442434;
    color: white;
    border-color: #5c3046;
}

.btn-import:hover {
    background: #5c3046;
    box-shadow: 0 0 15px rgba(68, 36, 52, 0.5);
}

.dropdown {
    background: var(--bg-panel);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 6px;
    font-family: inherit;
    outline: none;
}

/* Main Workspace */
.main-workspace {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Toolbar (Left) */
.toolbar {
    width: var(--toolbar-width);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 15px 0;
    gap: 10px;
    border-right: 1px solid var(--border-color);
    z-index: 5;
}

.tool-btn {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-secondary);
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    justify-content: center;
    align-items: center;
}

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

.tool-btn.active {
    background: rgba(99, 102, 241, 0.2);
    color: var(--accent-color);
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: inset 0 0 10px rgba(99, 102, 241, 0.1);
}

.spacer {
    flex: 1;
}

.color-preview-container {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    overflow: hidden;
    border: 2px solid var(--border-color);
    cursor: pointer;
    position: relative;
    background-image: 
        linear-gradient(45deg, #ccc 25%, transparent 25%), 
        linear-gradient(-45deg, #ccc 25%, transparent 25%), 
        linear-gradient(45deg, transparent 75%, #ccc 75%), 
        linear-gradient(-45deg, transparent 75%, #ccc 75%);
    background-size: 10px 10px;
    background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
    background-color: #eee;
}

.color-preview-container input[type="color"] {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    cursor: pointer;
    border: none;
    opacity: 0;
}

/* Canvas Area (Center) */
.canvas-area {
    flex: 1;
    display: flex;
    position: relative;
    background-color: #1a1a24;
    overflow: auto; /* Native scrollbars */
}

/* Checkered background for transparency visualization */
.canvas-wrapper {
    position: relative;
    margin: auto; /* Centers when small, allows full scrolling when large */
    flex-shrink: 0;
    background-image: 
        linear-gradient(45deg, #2a2a35 25%, transparent 25%), 
        linear-gradient(-45deg, #2a2a35 25%, transparent 25%), 
        linear-gradient(45deg, transparent 75%, #2a2a35 75%), 
        linear-gradient(-45deg, transparent 75%, #2a2a35 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    background-color: #202028;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    transition: width 0.1s ease-out, height 0.1s ease-out; /* Smooth zoom */
}

canvas {
    position: absolute;
    top: 0;
    left: 0;
    image-rendering: pixelated; /* Crucial for sharp pixels */
    cursor: crosshair;
}

#preview-canvas,
#grid-canvas {
    pointer-events: none; /* Let clicks pass through */
}

#grid-canvas {
    opacity: 0.5;
}

/* Zoom Controls */
.zoom-controls {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 8px 15px;
    border-radius: 20px;
}

#zoom-level {
    font-size: 0.9rem;
    font-weight: 500;
    min-width: 45px;
    text-align: center;
}

/* Right Sidebar */
.right-sidebar {
    width: var(--palette-width);
    display: flex;
    flex-direction: column;
    border-left: 1px solid var(--border-color);
    z-index: 5;
    background: var(--bg-panel);
}

/* Palette Panel */
.palette-panel {
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    border-bottom: 1px solid var(--border-color);
}

.palette-panel h3, .layers-header h3 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.swatches {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(30px, 1fr));
    gap: 8px;
}

.swatch {
    width: 100%;
    aspect-ratio: 1;
    border-radius: 4px;
    cursor: pointer;
    border: 1px solid rgba(255,255,255,0.2);
    transition: transform 0.1s;
}

.swatch:hover {
    transform: scale(1.1);
    border-color: white;
}

/* Tool Settings */
.divider-horizontal {
    width: 40px;
    height: 1px;
    background-color: var(--border-color);
    margin: 5px 0;
}

.tool-settings {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
}

.brush-size-container {
    display: flex;
    align-items: center;
    gap: 5px;
    color: var(--text-secondary);
    font-size: 0.8rem;
}

.brush-size-container input {
    width: 30px;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: 4px;
    padding: 2px;
    text-align: center;
    outline: none;
}

.toggle-btn {
    width: 30px;
    height: 30px;
    border-radius: 6px;
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    justify-content: center;
    align-items: center;
}

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

.toggle-btn.active {
    background: rgba(99, 102, 241, 0.2);
    color: var(--accent-color);
    border-color: rgba(99, 102, 241, 0.5);
}
/* Help Tooltip Overlay */
.help-btn-container {
    position: absolute;
    bottom: 20px;
    right: 20px;
    z-index: 100;
}

.help-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent-color);
    color: white;
    border: none;
    font-size: 1.2rem;
    cursor: help;
    opacity: 0.5;
    transition: all 0.3s ease;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.2);
    animation: pulse 2s infinite;
}

.help-btn:hover {
    opacity: 1;
    box-shadow: 0 0 20px rgba(99, 102, 241, 0.8);
    transform: scale(1.1);
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(99, 102, 241, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(99, 102, 241, 0); }
    100% { box-shadow: 0 0 0 0 rgba(99, 102, 241, 0); }
}

.help-tooltip {
    position: absolute;
    top: 50%;
    left: 100%;
    transform: translateY(-50%);
    margin-left: 10px;
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.8rem;
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s;
    z-index: 1000;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    border: 1px solid var(--accent-color);
}

.help-tooltip::before {
    content: '';
    position: absolute;
    top: 50%;
    right: 100%;
    transform: translateY(-50%);
    border-width: 5px;
    border-style: solid;
    border-color: transparent rgba(0, 0, 0, 0.8) transparent transparent;
}

/* Adjust tooltip position based on parent container */
.topbar .help-tooltip, 
.zoom-controls .help-tooltip {
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    margin-left: 0;
    margin-top: 10px;
}
.topbar .help-tooltip::before,
.zoom-controls .help-tooltip::before {
    top: -10px;
    right: auto;
    left: 50%;
    transform: translateX(-50%);
    border-color: transparent transparent rgba(0, 0, 0, 0.8) transparent;
}

.palette-panel .help-tooltip {
    left: auto;
    right: 100%;
    margin-left: 0;
    margin-right: 10px;
}
.palette-panel .help-tooltip::before {
    right: auto;
    left: 100%;
    border-color: transparent transparent transparent rgba(0, 0, 0, 0.8);
}

body.show-help .help-tooltip {
    opacity: 1;
    visibility: visible;
}

body.show-help .app-container::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.4);
    z-index: 99;
    pointer-events: none;
}
/* Bottom Bar */
.bottom-bar {
    height: 30px;
    display: flex;
    align-items: center;
    padding: 0 15px;
    background: var(--bg-panel);
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.8rem;
    z-index: 10;
}
.status-info {
    display: flex;
    align-items: center;
}
.status-info i {
    margin-right: 5px;
    color: var(--accent-color);
}

/* Layers Panel */
.layers-panel {
    display: flex;
    flex-direction: column;
    padding: 20px;
    flex: 1;
    gap: 10px;
    overflow: hidden;
}

.layers-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.layer-actions {
    display: flex;
    gap: 5px;
}

.layer-actions .btn {
    width: 24px;
    height: 24px;
    padding: 0;
    font-size: 0.75rem;
}

.layer-list {
    list-style: none;
    padding: 0;
    margin: 0;
    overflow-y: auto;
    display: flex;
    flex-direction: column-reverse; /* Bottom layer visually at bottom */
    gap: 5px;
}

.layer-item {
    display: flex;
    align-items: center;
    background: var(--bg-color);
    padding: 8px;
    border-radius: 6px;
    border: 1px solid transparent;
    cursor: pointer;
    gap: 10px;
}

.layer-item.active {
    border-color: var(--accent-color);
    background: rgba(99, 102, 241, 0.1);
}

.layer-item .layer-name {
    flex: 1;
    font-size: 0.85rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.layer-item .btn-visibility {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 2px;
}

.layer-item .btn-visibility:hover {
    color: var(--text-primary);
}