/* ===========================
   CSS Variables - Color Palette
   =========================== */
:root {
    /* Primary colors - warm and vibrant */
    --primary-blue: #4a90e2;
    --primary-purple: #7c5cdb;
    --primary-orange: #ff8a50;
    --primary-teal: #1abc9c;

    /* Neutral colors - Light Theme */
    --neutral-50: #fafbfc;
    --neutral-100: #f5f7fa;
    --neutral-200: #e4e9f0;
    --neutral-300: #cdd5e0;
    --neutral-400: #9aa5b5;
    --neutral-500: #6b7785;
    --neutral-600: #4a5568;
    --neutral-700: #2d3748;
    --neutral-800: #1a202c;
    --neutral-900: #0f1419;

    /* Semantic colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    /* Theme-specific colors */
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    --canvas-bg: linear-gradient(135deg, var(--neutral-300) 0%, var(--neutral-400) 50%, var(--neutral-300) 100%);
    --toolbox-bg: rgba(255, 255, 255, 0.95);
    --toolbox-border: rgba(255, 255, 255, 0.5);
    --header-bg: rgba(255, 255, 255, 0.15);
    --header-border: rgba(255, 255, 255, 0.3);
    --section-bg: rgba(255, 255, 255, 0.3);
    --section-bg-hover: rgba(255, 255, 255, 0.5);
    --btn-bg: linear-gradient(to bottom, white 0%, var(--neutral-50) 100%);
    --text-primary: var(--neutral-900);
    --text-secondary: var(--neutral-600);
    --text-inverse: white;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --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);

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

/* Dark Theme */
[data-theme="dark"] {
    /* Neutral colors - Dark Theme */
    --neutral-50: #18181b;
    --neutral-100: #27272a;
    --neutral-200: #3f3f46;
    --neutral-300: #52525b;
    --neutral-400: #71717a;
    --neutral-500: #a1a1aa;
    --neutral-600: #d4d4d8;
    --neutral-700: #e4e4e7;
    --neutral-800: #f4f4f5;
    --neutral-900: #fafafa;

    /* Theme-specific colors - Dark */
    --bg-gradient: linear-gradient(135deg, #1e1b4b 0%, #312e81 50%, #4c1d95 100%);
    --canvas-bg: linear-gradient(135deg, var(--neutral-200) 0%, var(--neutral-300) 50%, var(--neutral-200) 100%);
    --toolbox-bg: rgba(24, 24, 27, 0.95);
    --toolbox-border: rgba(82, 82, 91, 0.5);
    --header-bg: rgba(24, 24, 27, 0.8);
    --header-border: rgba(82, 82, 91, 0.4);
    --section-bg: rgba(39, 39, 42, 0.5);
    --section-bg-hover: rgba(63, 63, 70, 0.6);
    --btn-bg: linear-gradient(to bottom, var(--neutral-100) 0%, var(--neutral-50) 100%);
    --text-primary: var(--neutral-900);
    --text-secondary: var(--neutral-600);
    --text-inverse: var(--neutral-900);

    /* Shadows - Darker */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6), 0 10px 10px -5px rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-gradient);
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    color: var(--text-primary);
    transition: background var(--transition-slow), color var(--transition-base);
}

/* ===========================
   Full-Screen Canvas Container
   =========================== */
.canvas-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    background: var(--canvas-bg);
    z-index: 1;
    transition: background var(--transition-slow);
}

.canvas-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        linear-gradient(45deg, var(--neutral-200) 25%, transparent 25%),
        linear-gradient(-45deg, var(--neutral-200) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, var(--neutral-200) 75%),
        linear-gradient(-45deg, transparent 75%, var(--neutral-200) 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    opacity: 0.3;
    pointer-events: none;
}

/* Drag and drop visual feedback */
.canvas-container.drag-over::after {
    content: 'Drop image here';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 40px 60px;
    background: rgba(74, 144, 226, 0.95);
    color: white;
    font-size: 28px;
    font-weight: 600;
    border-radius: 16px;
    box-shadow:
        var(--shadow-xl),
        0 0 0 4px rgba(255, 255, 255, 0.3),
        0 0 60px rgba(74, 144, 226, 0.6);
    pointer-events: none;
    z-index: 1000;
    animation: pulse 1.5s ease-in-out infinite;
}

.canvas-container.drag-over {
    background: linear-gradient(135deg,
        rgba(74, 144, 226, 0.2) 0%,
        rgba(124, 92, 219, 0.2) 50%,
        rgba(74, 144, 226, 0.2) 100%);
}

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

#canvas {
    background-color: white;
    border: 4px solid var(--neutral-700);
    border-radius: 4px;
    box-shadow:
        var(--shadow-xl),
        0 0 0 1px rgba(255, 255, 255, 0.1) inset,
        0 0 40px rgba(0, 0, 0, 0.15);
    cursor: crosshair;
    transition: none;
    position: relative;
    z-index: 1;
    image-rendering: pixelated;
    image-rendering: crisp-edges;
}

/* ===========================
   Floating Header
   =========================== */
.floating-header {
    position: fixed;
    top: 20px;
    left: 20px;
    background: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--header-border);
    border-radius: 12px;
    padding: 12px 24px;
    box-shadow: var(--shadow-lg);
    z-index: 100;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: 12px;
}

.floating-header:hover {
    background: var(--section-bg-hover);
    box-shadow: var(--shadow-xl);
}

.floating-header h1 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-inverse);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    letter-spacing: 0.5px;
}

/* Theme Toggle Button */
.theme-toggle-btn {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    padding: 0;
}

.theme-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.theme-toggle-btn .theme-icon {
    font-size: 20px;
    transition: transform var(--transition-fast);
}

.theme-toggle-btn:hover .theme-icon {
    transform: rotate(20deg);
}

/* ===========================
   Floating Toolbox (Draggable)
   =========================== */
.floating-toolbox {
    position: fixed;
    top: 80px;
    right: 20px;
    width: 280px;
    max-height: calc(100vh - 120px);
    background: var(--toolbox-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--toolbox-border);
    border-radius: 16px;
    box-shadow: var(--shadow-xl);
    z-index: 101;
    overflow: hidden;
    transition: opacity var(--transition-base), transform var(--transition-base), background var(--transition-slow), border-color var(--transition-base);
}

.floating-toolbox.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateX(20px);
}

.floating-toolbox.minimized .toolbox-content {
    display: none;
}

.toolbox-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 18px;
    background: linear-gradient(135deg, var(--primary-purple) 0%, var(--primary-blue) 100%);
    cursor: move;
    user-select: none;
    border-radius: 16px 16px 0 0;
}

.toolbox-header:active {
    cursor: grabbing;
}

.toolbox-title {
    font-size: 16px;
    font-weight: 700;
    color: white;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.toolbox-toggle-btn {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 6px;
    width: 28px;
    height: 28px;
    color: white;
    font-size: 18px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.toolbox-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.toolbox-content {
    padding: 12px;
    max-height: calc(100vh - 200px);
    overflow-y: auto;
    overflow-x: hidden;
}

/* ===========================
   Tool Sections
   =========================== */
.tool-section {
    margin-bottom: 18px;
    padding: 14px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--neutral-200);
    background: var(--section-bg);
    border-radius: 8px;
    transition: background var(--transition-fast);
}

.tool-section:hover {
    background: var(--section-bg-hover);
}

.tool-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.section-label {
    font-size: 11px;
    font-weight: 700;
    color: var(--neutral-600);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
    padding-left: 2px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.section-label::before {
    content: '';
    width: 3px;
    height: 12px;
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-purple));
    border-radius: 2px;
}

/* Tool Buttons Layout */
.tool-buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.action-buttons {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

/* ===========================
   Buttons - Tool & Action
   =========================== */
.tool-btn, .action-btn {
    padding: 12px;
    border: 2px solid var(--neutral-300);
    background: var(--btn-bg);
    border-radius: 8px;
    cursor: pointer;
    font-size: 22px;
    font-weight: 400;
    line-height: 1;
    color: var(--text-primary);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    user-select: none;
}

.tool-btn:hover, .action-btn:hover {
    border-color: var(--primary-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.tool-btn:active, .action-btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.tool-btn.active {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-purple) 100%);
    border-color: var(--primary-purple);
    color: white;
    box-shadow: var(--shadow-md);
    transform: scale(1.05);
}

.action-btn {
    font-size: 16px;
    padding: 8px;
}

button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none !important;
    filter: grayscale(0.5);
}

button:disabled:hover {
    border-color: var(--neutral-300);
    box-shadow: var(--shadow-sm);
}

/* ===========================
   Control Rows
   =========================== */
.control-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.control-row:last-child {
    margin-bottom: 0;
}

.control-row label {
    font-size: 11px;
    font-weight: 600;
    color: var(--neutral-700);
    min-width: 65px;
    letter-spacing: 0.3px;
}

/* ===========================
   Form Controls
   =========================== */
#color-picker {
    width: 48px;
    height: 48px;
    border: 3px solid var(--neutral-300);
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

#color-picker:hover {
    border-color: var(--primary-teal);
    box-shadow: var(--shadow-md);
    transform: scale(1.05);
}

.color-swatch {
    width: 48px;
    height: 48px;
    border: 3px solid var(--neutral-300);
    border-radius: 8px;
    background-color: #000000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.color-swatch:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

input[type="range"] {
    flex: 1;
    min-width: 80px;
    accent-color: var(--primary-purple);
    cursor: pointer;
}

#brush-size-value, #fill-tolerance-value, #zoom-value {
    min-width: 35px;
    text-align: center;
    font-weight: 700;
    color: var(--primary-purple);
    font-size: 13px;
}

input[type="number"] {
    padding: 6px 8px;
    border: 2px solid var(--neutral-300);
    border-radius: 6px;
    font-size: 13px;
    text-align: center;
    transition: all var(--transition-base);
    background: white;
    width: 70px;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

input[type="number"]:hover {
    border-color: var(--primary-blue);
}

/* ===========================
   Color Palette System
   =========================== */
/* Primary & Secondary Color Swatches */
.color-swatches-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 12px;
}

.color-swatch-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    flex: 1;
}

.color-swatch-label {
    font-size: 10px;
    font-weight: 600;
    color: var(--neutral-600);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.color-swatch.large {
    width: 56px;
    height: 56px;
    cursor: pointer;
}

.color-swap-btn {
    width: 32px;
    height: 32px;
    background: linear-gradient(to bottom, white 0%, var(--neutral-50) 100%);
    border: 2px solid var(--neutral-300);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-top: 20px;
}

.color-swap-btn:hover {
    border-color: var(--primary-blue);
    transform: rotate(180deg);
    box-shadow: var(--shadow-md);
}

/* Color History */
.color-history-container,
.color-palette-container {
    margin-bottom: 12px;
}

.color-history-label,
.color-palette-label {
    font-size: 10px;
    font-weight: 600;
    color: var(--neutral-600);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.color-history,
.color-palette {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    gap: 6px;
}

.color-chip {
    width: 100%;
    aspect-ratio: 1;
    border: 2px solid var(--neutral-300);
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.color-chip:hover {
    transform: scale(1.15);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-blue);
    z-index: 10;
}

.color-chip.empty {
    background: repeating-linear-gradient(
        45deg,
        var(--neutral-100),
        var(--neutral-100) 2px,
        var(--neutral-200) 2px,
        var(--neutral-200) 4px
    );
    cursor: default;
}

.color-chip.empty:hover {
    transform: none;
    box-shadow: var(--shadow-sm);
    border-color: var(--neutral-300);
}

input[type="radio"] {
    margin-right: 4px;
    cursor: pointer;
    accent-color: var(--primary-purple);
    width: 16px;
    height: 16px;
}

select {
    padding: 6px 10px;
    border: 2px solid var(--neutral-300);
    border-radius: 6px;
    font-size: 13px;
    cursor: pointer;
    background: white;
    transition: all var(--transition-base);
    font-weight: 500;
    flex: 1;
}

select:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

select:hover {
    border-color: var(--primary-blue);
}

/* ===========================
   Floating Status Bar
   =========================== */
.floating-status {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 20px;
    padding: 12px 24px;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 24px;
    color: white;
    font-size: 13px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 100;
    transition: all var(--transition-base);
}

.floating-status:hover {
    background: rgba(0, 0, 0, 0.85);
    box-shadow: var(--shadow-xl);
}

.floating-status span {
    white-space: nowrap;
}

/* ===========================
   Text Input Overlay
   =========================== */
.text-input-overlay {
    position: absolute;
    display: none;
    border: 2px solid var(--primary-blue);
    background-color: rgba(255, 255, 255, 0.95);
    padding: 6px;
    outline: none;
    z-index: 100;
    border-radius: 4px;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
}

.text-input-overlay.active {
    display: block;
    animation: fadeIn var(--transition-base);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* ===========================
   Modal Styles
   =========================== */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    justify-content: center;
    align-items: center;
    animation: modalFadeIn var(--transition-base);
}

.modal.active {
    display: flex;
}

@keyframes modalFadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal-content {
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-xl);
    max-width: 650px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    animation: modalSlideIn var(--transition-slow);
}

@keyframes modalSlideIn {
    from {
        transform: translateY(-50px) scale(0.95);
        opacity: 0;
    }
    to {
        transform: translateY(0) scale(1);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px;
    border-bottom: 2px solid var(--neutral-200);
    background: linear-gradient(135deg, var(--neutral-50) 0%, white 100%);
    border-radius: 12px 12px 0 0;
}

.modal-header h2 {
    margin: 0;
    background: linear-gradient(135deg, var(--primary-purple) 0%, var(--primary-blue) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 26px;
    font-weight: 700;
}

.close-btn {
    background: var(--neutral-100);
    border: 2px solid var(--neutral-200);
    border-radius: 50%;
    font-size: 28px;
    color: var(--neutral-500);
    cursor: pointer;
    padding: 0;
    width: 44px;
    height: 44px;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all var(--transition-base);
}

.close-btn:hover {
    background: var(--error);
    color: white;
    border-color: var(--error);
    transform: rotate(90deg) scale(1.1);
}

.modal-body {
    padding: 24px;
}

.shortcuts-section {
    margin-bottom: 28px;
}

.shortcuts-section:last-child {
    margin-bottom: 0;
}

.shortcuts-section h3 {
    color: var(--neutral-700);
    margin-bottom: 12px;
    font-size: 19px;
    font-weight: 700;
    border-bottom: 2px solid var(--primary-blue);
    padding-bottom: 8px;
    background: linear-gradient(90deg, var(--primary-blue) 0%, transparent 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.shortcuts-table {
    width: 100%;
    border-collapse: collapse;
}

.shortcuts-table tr {
    border-bottom: 1px solid var(--neutral-200);
    transition: background var(--transition-fast);
}

.shortcuts-table tr:hover {
    background: var(--neutral-50);
}

.shortcuts-table tr:last-child {
    border-bottom: none;
}

.shortcuts-table td {
    padding: 12px;
    color: var(--neutral-600);
}

.shortcuts-table td:first-child {
    font-weight: 600;
    width: 180px;
    color: var(--neutral-700);
}

kbd {
    display: inline-block;
    padding: 5px 10px;
    font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
    font-size: 13px;
    font-weight: 600;
    color: var(--neutral-700);
    background: linear-gradient(to bottom, var(--neutral-100) 0%, var(--neutral-200) 100%);
    border: 2px solid var(--neutral-300);
    border-radius: 5px;
    box-shadow:
        0 1px 0 var(--neutral-400),
        0 2px 4px rgba(0, 0, 0, 0.1);
    margin: 0 3px;
    transition: all var(--transition-fast);
}

kbd:hover {
    transform: translateY(-1px);
    box-shadow:
        0 2px 0 var(--neutral-400),
        0 3px 6px rgba(0, 0, 0, 0.15);
}

/* ===========================
   Scrollbar Styling
   =========================== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--neutral-100);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, var(--primary-purple) 0%, var(--primary-blue) 100%);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-teal) 100%);
}

/* ===========================
   Loading Overlay
   =========================== */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: none;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    gap: 20px;
    z-index: 1000;
    animation: fadeIn var(--transition-base);
}

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

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: var(--primary-teal);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-text {
    color: white;
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ===========================
   Layer Panel Styles
   =========================== */

.layer-controls {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    margin-bottom: 12px;
}

.layer-control-btn {
    padding: 8px;
    border: 2px solid var(--neutral-300);
    background: white;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 700;
    transition: all var(--transition-base);
    color: var(--neutral-700);
}

.layer-control-btn:hover {
    background: linear-gradient(135deg, var(--primary-blue), var(--primary-purple));
    color: white;
    border-color: var(--primary-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.layer-control-btn:active {
    transform: translateY(0);
}

.layer-control-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.layer-list {
    max-height: 300px;
    overflow-y: auto;
    border: 2px solid var(--neutral-200);
    border-radius: 8px;
    background: var(--neutral-50);
    padding: 4px;
}

.layer-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px;
    border-radius: 6px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-bottom: 4px;
    background: white;
}

.layer-item:hover {
    background: var(--neutral-100);
    border-color: var(--neutral-300);
}

.layer-item.active {
    background: linear-gradient(135deg, rgba(74, 144, 226, 0.15), rgba(124, 92, 219, 0.15));
    border-color: var(--primary-blue);
    border-left-width: 4px;
    box-shadow: var(--shadow-sm);
}

.layer-item.dragging {
    opacity: 0.5;
    cursor: grabbing;
}

.layer-item.drag-over {
    border-top: 3px solid var(--accent-color);
    padding-top: 9px; /* 12px - 3px to maintain height */
}

.layer-thumbnail {
    width: 60px;
    height: 45px;
    min-width: 60px;
    border: 2px solid var(--neutral-300);
    border-radius: 4px;
    overflow: hidden;
    background: white;
    background-image:
        linear-gradient(45deg, var(--neutral-100) 25%, transparent 25%),
        linear-gradient(-45deg, var(--neutral-100) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, var(--neutral-100) 75%),
        linear-gradient(-45deg, transparent 75%, var(--neutral-100) 75%);
    background-size: 10px 10px;
    background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
}

.layer-thumbnail canvas {
    width: 100%;
    height: 100%;
    image-rendering: pixelated;
}

.layer-info {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.layer-name {
    font-size: 13px;
    font-weight: 600;
    color: var(--neutral-700);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    cursor: pointer;
}

.layer-name:hover {
    color: var(--primary-color);
}

.layer-name-input {
    font-size: 13px;
    font-weight: 600;
    color: var(--neutral-700);
    background: var(--neutral-100);
    border: 2px solid var(--primary-color);
    border-radius: 4px;
    padding: 2px 6px;
    outline: none;
    width: 100%;
}

.layer-controls-row {
    display: flex;
    align-items: center;
    gap: 6px;
}

.layer-visibility-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 16px;
    padding: 2px 4px;
    opacity: 0.4;
    transition: opacity var(--transition-fast);
    filter: grayscale(100%);
}

.layer-visibility-btn.visible {
    opacity: 1.0;
    filter: grayscale(0%);
}

.layer-visibility-btn:hover {
    opacity: 1.0;
    filter: grayscale(0%);
}

.layer-opacity-slider {
    flex: 1;
    min-width: 60px;
    height: 4px;
    border-radius: 2px;
    background: var(--neutral-200);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.layer-opacity-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--primary-teal);
    cursor: pointer;
    border: 2px solid white;
    box-shadow: var(--shadow-sm);
}

.layer-opacity-slider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--primary-teal);
    cursor: pointer;
    border: 2px solid white;
    box-shadow: var(--shadow-sm);
}

.layer-opacity-value {
    font-size: 11px;
    font-weight: 600;
    color: var(--neutral-600);
    min-width: 35px;
    text-align: center;
}

.layer-blend-mode-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 4px;
}

.layer-blend-mode-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--neutral-600);
    min-width: 40px;
}

.layer-blend-mode-select {
    flex: 1;
    padding: 2px 4px;
    font-size: 11px;
    background: var(--neutral-100);
    border: 1px solid var(--neutral-300);
    border-radius: 3px;
    color: var(--neutral-700);
    cursor: pointer;
    outline: none;
    transition: border-color var(--transition-fast);
}

.layer-blend-mode-select:hover {
    border-color: var(--primary-teal);
}

.layer-blend-mode-select:focus {
    border-color: var(--primary-teal);
    box-shadow: 0 0 0 2px rgba(26, 188, 156, 0.2);
}

.layer-reorder {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.layer-move-up,
.layer-move-down {
    background: var(--neutral-100);
    border: 1px solid var(--neutral-300);
    border-radius: 4px;
    padding: 2px 6px;
    cursor: pointer;
    font-size: 11px;
    font-weight: 700;
    color: var(--neutral-600);
    transition: all var(--transition-fast);
    line-height: 1;
}

.layer-move-up:hover,
.layer-move-down:hover {
    background: var(--primary-blue);
    color: white;
    border-color: var(--primary-blue);
    transform: scale(1.1);
}

.layer-move-up:active,
.layer-move-down:active {
    transform: scale(0.95);
}

.layer-move-up:disabled,
.layer-move-down:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
}