:root {
            --bg-color: #080a16;
            --card-bg: rgba(15, 18, 36, 0.65);
            --border-color: rgba(255, 255, 255, 0.08);
            --accent-primary: #00e5ff;
            --accent-secondary: #bd00ff;
            --text-main: #f3f4f6;
            --text-muted: #9ca3af;
            --success: #10b981;
            --shadow-glow: 0 0 20px rgba(0, 229, 255, 0.25);
            --font-family: 'Outfit', sans-serif;
        }

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

        body {
            background-color: var(--bg-color);
            color: var(--text-main);
            font-family: var(--font-family);
            height: 100vh;
            display: flex;
            flex-direction: column;
            overflow: hidden;
            background-image: 
                radial-gradient(at 10% 20%, rgba(189, 0, 255, 0.1) 0px, transparent 50%),
                radial-gradient(at 90% 80%, rgba(0, 229, 255, 0.08) 0px, transparent 50%);
        }

        header {
            position: sticky;
            top: 0;
            padding: 1rem 1.75rem;
            border-bottom: 1px solid var(--border-color);
            background: rgba(8, 10, 22, 0.88);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            z-index: 100;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 0.75rem;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.45);
        }

        .logo-container {
            display: flex;
            align-items: center;
            gap: 0.75rem;
        }

        .logo-glow {
            width: 14px;
            height: 14px;
            background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
            border-radius: 50%;
            box-shadow: var(--shadow-glow);
            animation: pulse 3s infinite ease-in-out;
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); opacity: 0.8; }
            50% { transform: scale(1.3); opacity: 1; filter: brightness(1.2); }
        }

        h1 {
            font-weight: 800;
            font-size: 1.5rem;
            letter-spacing: 0.1em;
            background: linear-gradient(135deg, #fff 30%, #a5b4fc);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            text-transform: uppercase;
        }

        .subtitle {
            font-size: 0.85rem;
            color: var(--text-muted);
            font-weight: 300;
        }

        main {
            flex: 1;
            display: grid;
            grid-template-columns: 1fr;
            height: 100%;
            min-height: 0;
            overflow: hidden;
            padding-bottom: 64px;
        }

        /* Left Control Panel (Tab 1: Design Controls) */
        .control-panel {
            background: var(--card-bg);
            border-right: none;
            backdrop-filter: blur(15px);
            padding: 2rem 1.5rem;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1.5rem;
            width: 100%;
            height: 100%;
            min-height: 0;
            overflow-y: auto;
            position: relative;
        }
        .control-panel > * {
            width: 100%;
            max-width: 760px;
        }

        .control-panel::-webkit-scrollbar {
            width: 8px;
        }
        .control-panel::-webkit-scrollbar-track {
            background: rgba(8, 10, 22, 0.4);
        }
        .control-panel::-webkit-scrollbar-thumb {
            background: rgba(255, 255, 255, 0.18);
            border-radius: 4px;
        }
        .control-panel::-webkit-scrollbar-thumb:hover {
            background: rgba(0, 229, 255, 0.4);
        }

        /* File Upload */
        .upload-container {
            border: 2px dashed rgba(255, 255, 255, 0.22);
            border-radius: 16px;
            padding: 2.8rem 1.75rem;
            min-height: 200px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            background: rgba(255, 255, 255, 0.025);
            position: relative;
            overflow: visible;
            flex-shrink: 0;
        }

        .upload-container:hover {
            border-color: var(--accent-primary);
            background: rgba(0, 229, 255, 0.04);
            box-shadow: 0 0 25px rgba(0, 229, 255, 0.15);
        }

        .upload-container.dragover {
            border-color: var(--accent-secondary);
            background: rgba(189, 0, 255, 0.05);
        }

        .upload-icon {
            font-size: 2.5rem;
            margin-bottom: 0.85rem;
            color: var(--accent-primary);
            transition: transform 0.3s;
        }

        .upload-container:hover .upload-icon {
            transform: translateY(-3px);
        }

        .upload-text {
            font-size: 1.05rem;
            color: var(--text-main);
            font-weight: 600;
            margin-bottom: 0.4rem;
            line-height: 1.4;
            word-break: break-word;
            overflow-wrap: anywhere;
        }

        .upload-hint {
            font-size: 0.82rem;
            color: var(--text-muted);
            line-height: 1.4;
            word-break: break-word;
            overflow-wrap: anywhere;
        }

        .upload-container.has-image .upload-icon,
        .upload-container.has-image .upload-hint {
            display: none !important;
        }

        .upload-container.has-image .upload-text {
            position: absolute;
            bottom: 12px;
            left: 50%;
            transform: translateX(-50%);
            background: rgba(10, 15, 30, 0.88);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(0, 229, 255, 0.35);
            padding: 0.35rem 0.95rem;
            border-radius: 99px;
            font-size: 0.88rem;
            font-weight: 700;
            color: #00e5ff;
            box-shadow: 0 4px 18px rgba(0, 0, 0, 0.65);
            margin: 0;
            max-width: 90%;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            z-index: 5;
        }

        .upload-container.has-image:hover::after {
            content: "Click or drag to replace image";
            position: absolute;
            top: 12px;
            left: 50%;
            transform: translateX(-50%);
            background: rgba(0, 229, 255, 0.95);
            color: #050b14;
            font-size: 0.78rem;
            font-weight: 800;
            padding: 0.3rem 0.85rem;
            border-radius: 99px;
            box-shadow: 0 4px 15px rgba(0, 229, 255, 0.45);
            z-index: 6;
            pointer-events: none;
        }

        #file-input {
            display: none;
        }

        /* Settings Card Group */
        .settings-group {
            display: flex;
            flex-direction: column;
            gap: 1.25rem;
            opacity: 0.4;
            pointer-events: none;
            transition: opacity 0.3s ease;
        }

        .settings-group.active {
            opacity: 1;
            pointer-events: auto;
        }

        .accordion-card {
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid var(--border-color);
            border-radius: 10px;
            overflow: hidden;
            transition: border-color 0.3s ease, box-shadow 0.3s ease;
        }

        .accordion-card:hover {
            border-color: rgba(0, 229, 255, 0.35);
        }

        .accordion-header {
            padding: 1rem 1.25rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
            cursor: pointer;
            user-select: none;
            background: rgba(255, 255, 255, 0.02);
            border-bottom: 1px solid var(--border-color);
            transition: background 0.2s ease;
        }

        .accordion-card.collapsed .accordion-header {
            border-bottom: none;
        }

        .accordion-header:hover {
            background: rgba(255, 255, 255, 0.06);
        }

        .accordion-title {
            font-size: 0.85rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--text-main);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .accordion-chevron {
            font-size: 0.75rem;
            color: var(--text-muted);
            transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .accordion-card.collapsed .accordion-chevron {
            transform: rotate(-90deg);
        }

        .accordion-body {
            padding: 1.25rem;
            max-height: 1500px;
            opacity: 1;
            transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.25s ease, padding 0.35s ease;
        }

        .accordion-card.collapsed .accordion-body {
            max-height: 0;
            padding-top: 0;
            padding-bottom: 0;
            opacity: 0;
            overflow: hidden;
        }

        .settings-section {
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 1.25rem;
        }

        .section-title {
            font-size: 0.85rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: var(--text-muted);
            margin-bottom: 1rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        /* Sliders */
        .slider-wrapper {
            margin-bottom: 1rem;
        }

        .slider-wrapper:last-child {
            margin-bottom: 0;
        }

        .slider-header {
            display: flex;
            justify-content: space-between;
            font-size: 0.85rem;
            margin-bottom: 0.5rem;
        }

        .slider-label {
            color: var(--text-main);
            font-weight: 400;
        }

        .slider-value {
            color: var(--accent-primary);
            font-weight: 600;
        }

        input[type="range"] {
            -webkit-appearance: none;
            appearance: none;
            width: 100%;
            height: 6px;
            border-radius: 3px;
            background: rgba(255, 255, 255, 0.1);
            outline: none;
            transition: background 0.3s;
        }

        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            appearance: none;
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background: var(--accent-primary);
            cursor: pointer;
            transition: transform 0.1s, background-color 0.2s;
            box-shadow: 0 0 8px rgba(0, 229, 255, 0.5);
        }

        input[type="range"]::-webkit-slider-thumb:hover {
            transform: scale(1.25);
            background: #ffffff;
        }

        .toggle-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
            cursor: pointer;
        }

        .toggle-row input[type="checkbox"] {
            appearance: none;
            width: 40px;
            height: 22px;
            background: rgba(255, 255, 255, 0.15);
            border-radius: 11px;
            position: relative;
            cursor: pointer;
            outline: none;
            transition: background 0.3s;
        }

        .toggle-row input[type="checkbox"]:checked {
            background: var(--accent-primary);
            box-shadow: 0 0 10px rgba(0, 229, 255, 0.4);
        }

        .toggle-row input[type="checkbox"]::after {
            content: '';
            position: absolute;
            top: 3px;
            left: 3px;
            width: 16px;
            height: 16px;
            background: #fff;
            border-radius: 50%;
            transition: transform 0.3s;
        }

        .toggle-row input[type="checkbox"]:checked::after {
            transform: translateX(18px);
        }

        .custom-select {
            width: 100%;
            background: rgba(15, 18, 36, 0.85);
            color: var(--text-main);
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 8px 10px;
            font-family: var(--font-family);
            font-size: 0.85rem;
            outline: none;
            margin-bottom: 1rem;
            cursor: pointer;
        }

        .custom-select:focus {
            border-color: var(--accent-primary);
        }


        /* Color Palette & Pane Thickness List */
        .palette-list {
            display: flex;
            flex-direction: column;
            gap: 0.6rem;
            margin-top: 0.75rem;
            max-height: 320px;
            overflow-y: auto;
            padding-right: 4px;
        }

        .palette-item {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 0.75rem;
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 0.6rem 0.8rem;
            transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .palette-item:hover {
            background: rgba(255, 255, 255, 0.06);
            border-color: rgba(255, 255, 255, 0.2);
        }

        .palette-item.is-frame {
            border-color: var(--accent-primary);
            background: rgba(0, 229, 255, 0.08);
            box-shadow: 0 0 15px rgba(0, 229, 255, 0.15);
        }

        .palette-left {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            flex: 1;
        }

        .palette-swatch {
            width: 32px;
            height: 32px;
            border-radius: 8px;
            border: 2px solid rgba(255, 255, 255, 0.25);
            flex-shrink: 0;
            box-shadow: 0 2px 6px rgba(0,0,0,0.4);
            cursor: pointer;
            position: relative;
        }

        .palette-item.is-frame .palette-swatch::after {
            content: "✓";
            color: #fff;
            font-size: 0.8rem;
            font-weight: 900;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            text-shadow: 0 1px 3px rgba(0,0,0,0.9);
        }

        .palette-info {
            display: flex;
            flex-direction: column;
            gap: 0.2rem;
        }

        .palette-hex {
            font-size: 0.85rem;
            font-weight: 700;
            color: var(--text-main);
            font-family: monospace;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .palette-badge {
            font-size: 0.65rem;
            padding: 2px 6px;
            border-radius: 4px;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.5px;
            font-family: system-ui, -apple-system, sans-serif;
        }

        .palette-badge.translucent {
            background: rgba(0, 229, 255, 0.15);
            color: #00e5ff;
            border: 1px solid rgba(0, 229, 255, 0.3);
        }

        .palette-badge.opaque {
            background: rgba(255, 255, 255, 0.1);
            color: var(--text-muted);
            border: 1px solid var(--border-color);
        }

        .palette-role-btn {
            font-size: 0.7rem;
            padding: 3px 8px;
            border-radius: 6px;
            background: rgba(255, 255, 255, 0.05);
            border: 1px solid var(--border-color);
            color: var(--text-muted);
            cursor: pointer;
            transition: all 0.2s;
            width: fit-content;
        }

        .palette-item.is-frame .palette-role-btn {
            background: var(--accent-primary);
            border-color: var(--accent-primary);
            color: #0a0b10;
            font-weight: 700;
        }

        .palette-thickness-wrap {
            display: flex;
            flex-direction: column;
            gap: 0.3rem;
            width: 140px;
        }

        .palette-thickness-header {
            display: flex;
            justify-content: space-between;
            align-items: baseline;
            font-size: 0.7rem;
            color: var(--text-muted);
        }

        .palette-thickness-val {
            color: var(--text-main);
            font-weight: 700;
            font-size: 0.75rem;
        }

        .palette-item.is-frame .palette-thickness-wrap {
            opacity: 0.4;
            pointer-events: none;
        }

        /* Preview Display */
        .preview-box {
            display: flex;
            gap: 1rem;
            margin-top: 0.5rem;
        }

        .preview-thumbnail {
            flex: 1;
            aspect-ratio: 1;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            background: rgba(0, 0, 0, 0.2);
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: hidden;
            position: relative;
        }

        .preview-thumbnail img {
            max-width: 100%;
            max-height: 100%;
            object-fit: contain;
        }

        .preview-label {
            position: absolute;
            bottom: 4px;
            left: 4px;
            background: rgba(0, 0, 0, 0.6);
            padding: 2px 6px;
            border-radius: 4px;
            font-size: 0.65rem;
            color: var(--text-muted);
        }

        /* Action Buttons */
        .btn {
            background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
            color: #fff;
            border: none;
            border-radius: 10px;
            padding: 1rem;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            width: 100%;
            display: flex;
            justify-content: center;
            align-items: center;
            gap: 0.5rem;
            box-shadow: 0 4px 15px rgba(189, 0, 255, 0.2);
            text-decoration: none;
        }

        .btn:hover:not(:disabled) {
            filter: brightness(1.1);
            box-shadow: 0 4px 20px rgba(0, 229, 255, 0.4);
            transform: translateY(-2px);
        }

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

        .btn:disabled {
            background: rgba(255, 255, 255, 0.05);
            color: var(--text-muted);
            cursor: not-allowed;
            box-shadow: none;
        }

        .btn-secondary {
            background: rgba(255, 255, 255, 0.08);
            border: 1px solid var(--border-color);
            box-shadow: none;
        }

        .btn-secondary:hover:not(:disabled) {
            background: rgba(255, 255, 255, 0.15);
            box-shadow: none;
        }

        /* Right Viewport (Tab 2: 3D / 2D Studio) */
        .viewer-container {
            position: relative;
            width: 100%;
            height: 100%;
            min-height: 0;
            overflow: hidden;
            background: radial-gradient(circle at center, #1e293b 0%, #0f172a 100%);
            display: none;
            align-items: center;
            justify-content: center;
        }

        .viewer-container.bg-light {
            background: radial-gradient(circle at center, #f8fafc 0%, #cbd5e1 100%);
        }

        .viewer-container.bg-grid {
            background: #0f172a radial-gradient(rgba(255, 255, 255, 0.1) 1px, transparent 0);
            background-size: 24px 24px;
        }

        /* Universal Dual/Triple-Tab Workspace Switcher Rules */
        .control-panel {
            display: flex;
        }
        .viewer-container {
            display: none;
        }
        .workspace-panel {
            background: var(--card-bg);
            backdrop-filter: blur(15px);
            padding: 2.5rem 1.5rem;
            display: none;
            flex-direction: column;
            align-items: center;
            width: 100%;
            height: 100%;
            overflow-y: auto;
            box-sizing: border-box;
        }
        .workspace-panel-content {
            max-width: 900px;
            width: 100%;
            margin: 0 auto;
        }

        main.mobile-view-preview .control-panel,
        main.tab-view-preview .control-panel,
        main.mobile-view-workspace .control-panel,
        main.tab-view-workspace .control-panel {
            display: none !important;
        }

        main.mobile-view-preview .viewer-container,
        main.tab-view-preview .viewer-container {
            display: flex !important;
        }
        main.mobile-view-workspace .viewer-container,
        main.tab-view-workspace .viewer-container {
            display: none !important;
        }

        main.mobile-view-workspace .workspace-panel,
        main.tab-view-workspace .workspace-panel {
            display: flex !important;
        }

        #canvas-3d {
            width: 100%;
            height: 100%;
            display: block;
        }

        /* Viewer Instructions overlay */
        .viewer-hint {
            position: absolute;
            bottom: 1.5rem;
            left: 50%;
            transform: translateX(-50%);
            background: rgba(8, 10, 22, 0.75);
            border: 1px solid var(--border-color);
            padding: 0.5rem 1rem;
            border-radius: 20px;
            font-size: 0.75rem;
            color: var(--text-muted);
            pointer-events: none;
            backdrop-filter: blur(5px);
            z-index: 5;
            display: none;
        }

        /* Lighting Preset Controls Overlay */
        .light-presets {
            position: absolute;
            top: 1.5rem;
            right: 1.5rem;
            background: rgba(8, 10, 22, 0.75);
            border: 1px solid var(--border-color);
            padding: 0.5rem;
            border-radius: 8px;
            backdrop-filter: blur(5px);
            z-index: 5;
            display: none;
            flex-direction: column;
            gap: 0.4rem;
        }

        .preset-title {
            font-size: 0.65rem;
            color: var(--text-muted);
            text-transform: uppercase;
            font-weight: 600;
            padding: 2px 6px;
        }

        .preset-btn {
            background: transparent;
            border: none;
            color: var(--text-muted);
            padding: 4px 8px;
            font-size: 0.75rem;
            cursor: pointer;
            border-radius: 4px;
            text-align: left;
            transition: all 0.2s;
        }

        .preset-btn:hover {
            background: rgba(255, 255, 255, 0.05);
            color: #fff;
        }

        .preset-btn.active {
            background: rgba(0, 229, 255, 0.15);
            color: var(--accent-primary);
            font-weight: 600;
        }

        /* Loading Screen Overlay */
        .loading-overlay {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(8, 10, 22, 0.9);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: flex-start;
            padding-top: 12vh;
            z-index: 8;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s ease;
        }

        .loading-overlay.active {
            opacity: 1;
            pointer-events: auto;
        }

        .spinner {
            width: 50px;
            height: 50px;
            border: 3px solid rgba(0, 229, 255, 0.1);
            border-top-color: var(--accent-primary);
            border-radius: 50%;
            animation: spin 1s infinite linear;
            margin-bottom: 1.5rem;
            box-shadow: var(--shadow-glow);
        }

        @keyframes spin {
            100% { transform: rotate(360deg); }
        }

        .loading-title {
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: 0.75rem;
            color: #fff;
        }

        .loading-step {
            font-size: 0.85rem;
            color: var(--text-muted);
            transition: color 0.2s;
        }

        .loading-step.active {
            color: var(--accent-primary);
            font-weight: 600;
        }

        /* Centered welcome message when viewport is empty */
        .welcome-view {
            position: absolute;
            text-align: center;
            max-width: 350px;
            padding: 2rem;
            z-index: 2;
            transition: opacity 0.3s ease;
            pointer-events: none;
        }

        .welcome-view.hidden {
            opacity: 0;
        }

        .welcome-icon {
            font-size: 3.5rem;
            margin-bottom: 1rem;
            background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
            display: inline-block;
        }

        .welcome-title {
            font-size: 1.25rem;
            font-weight: 600;
            margin-bottom: 0.5rem;
        }

        .welcome-desc {
            font-size: 0.85rem;
            color: var(--text-muted);
            line-height: 1.4;
        }
        /* Ad Slot / Revenue Container in Welcome Viewport (Simple Google AdSense Window) */
        .ad-showcase-box {
            margin-top: 1.5rem;
            width: 100%;
            max-width: 728px;
            background: rgba(10, 13, 28, 0.75);
            border: 1px dashed rgba(255, 255, 255, 0.15);
            border-radius: 12px;
            padding: 1.2rem;
            position: relative;
            box-shadow: inset 0 0 25px rgba(0, 0, 0, 0.5);
        }

        .ad-showcase-header {
            font-size: 0.68rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 1.5px;
            color: rgba(156, 163, 175, 0.65);
            margin-bottom: 0.75rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .ad-slot-body {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            width: 100%;
            min-height: 260px;
            background: rgba(18, 22, 44, 0.65);
            border-radius: 8px;
            padding: 1rem;
            color: var(--text-main);
            text-align: center;
            border: 1px solid rgba(0, 229, 255, 0.2);
            overflow: hidden;
        }

        /* Email Sign-up Popover Modal */
        .modal-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100vw;
            height: 100vh;
            background: rgba(8, 10, 22, 0.82);
            backdrop-filter: blur(10px);
            z-index: 9999;
            display: flex;
            align-items: center;
            justify-content: center;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .modal-overlay.active {
            opacity: 1;
            pointer-events: auto;
        }

        .signup-modal-card {
            background: linear-gradient(145deg, rgba(20, 24, 48, 0.95), rgba(12, 14, 28, 0.95));
            border: 1px solid rgba(0, 229, 255, 0.2);
            border-radius: 20px;
            width: 90%;
            max-width: 440px;
            padding: 2.2rem;
            position: relative;
            box-shadow: 0 20px 50px rgba(0, 0, 0, 0.7), 0 0 30px rgba(0, 229, 255, 0.12);
            transform: translateY(20px) scale(0.95);
            transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .modal-overlay.active .signup-modal-card {
            transform: translateY(0) scale(1);
        }

        /* High-contrast close button 'X' for Pro Benefits, Pro Workspace, and other modals */
        .modal-close-btn,
        #close-pro-benefits-btn,
        #close-workspace-btn {
            position: absolute;
            top: 16px;
            right: 16px;
            background: rgba(255, 255, 255, 0.18);
            border: 1.5px solid rgba(255, 255, 255, 0.55);
            color: #ffffff; /* High contrast crisp white */
            font-size: 1.45rem;
            font-weight: 800;
            cursor: pointer;
            width: 34px;
            height: 34px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            transition: all 0.2s ease;
            z-index: 100;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
            line-height: 1;
        }

        .modal-close-btn:hover,
        #close-pro-benefits-btn:hover,
        #close-workspace-btn:hover {
            background: var(--accent-primary);
            border-color: var(--accent-primary);
            color: #080a16;
            transform: scale(1.12);
            box-shadow: 0 0 16px rgba(0, 229, 255, 0.7);
        }

        .signup-modal-title {
            font-size: 1.4rem;
            font-weight: 800;
            color: #fff;
            margin-bottom: 0.5rem;
            background: linear-gradient(135deg, #fff 0%, var(--accent-primary) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .signup-modal-desc {
            font-size: 0.9rem;
            color: var(--text-muted);
            line-height: 1.5;
            margin-bottom: 1.5rem;
        }

        .signup-input-group {
            display: flex;
            flex-direction: column;
            gap: 0.85rem;
        }

        .signup-input {
            width: 100%;
            background: rgba(8, 10, 22, 0.8);
            border: 1px solid rgba(255, 255, 255, 0.12);
            border-radius: 10px;
            padding: 0.85rem 1rem;
            color: #fff;
            font-family: var(--font-family);
            font-size: 0.95rem;
            outline: none;
            transition: border-color 0.2s ease;
        }

        .signup-input:focus {
            border-color: var(--accent-primary);
        }

        /* Pro Benefits & Workspace Modals */
        .pro-modal-card {
            background: linear-gradient(145deg, rgba(18, 22, 45, 0.95), rgba(10, 13, 28, 0.97));
            border: 1px solid rgba(0, 229, 255, 0.28);
            border-radius: 20px;
            padding: 2.2rem;
            max-width: 680px;
            width: 92%;
            box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8), 0 0 40px rgba(0, 229, 255, 0.12);
            position: relative;
            backdrop-filter: blur(20px);
            max-height: 90vh;
            overflow-y: auto;
        }

        .pro-features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.1rem;
            margin: 1.5rem 0;
        }

        .pro-feature-card {
            background: rgba(255, 255, 255, 0.035);
            border: 1px solid rgba(255, 255, 255, 0.08);
            border-radius: 14px;
            padding: 1.25rem;
            transition: all 0.25s ease;
        }

        .pro-feature-card:hover {
            border-color: rgba(0, 229, 255, 0.35);
            background: rgba(0, 229, 255, 0.05);
            transform: translateY(-2px);
        }

        .pro-feature-icon {
            font-size: 1.8rem;
            margin-bottom: 0.6rem;
        }

        .pro-feature-title {
            font-size: 1.05rem;
            font-weight: 700;
            color: #fff;
            margin-bottom: 0.35rem;
        }

        .pro-feature-desc {
            font-size: 0.85rem;
            color: var(--text-muted);
            line-height: 1.5;
        }

        .workspace-modal-card {
            background: linear-gradient(145deg, rgba(15, 20, 38, 0.97), rgba(8, 10, 22, 0.98));
            border: 1px solid rgba(165, 180, 252, 0.3);
            border-radius: 20px;
            padding: 2.2rem;
            max-width: 820px;
            width: 94%;
            box-shadow: 0 25px 60px rgba(0, 0, 0, 0.85), 0 0 40px rgba(124, 58, 237, 0.15);
            position: relative;
            backdrop-filter: blur(20px);
            max-height: 90vh;
            overflow-y: auto;
        }

        .workspace-projects-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
            gap: 1.25rem;
            margin-top: 1.5rem;
        }

        .workspace-project-card {
            background: rgba(30, 41, 59, 0.4);
            border: 1px solid rgba(255, 255, 255, 0.1);
            border-radius: 14px;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            transition: all 0.2s ease;
        }

        .workspace-project-card:hover {
            border-color: rgba(0, 229, 255, 0.4);
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
        }

        .workspace-project-thumb {
            width: 100%;
            height: 140px;
            object-fit: contain;
            background: rgba(0, 0, 0, 0.5);
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
        }

        .workspace-project-info {
            padding: 1rem;
            display: flex;
            flex-direction: column;
            flex-grow: 1;
        }

        .workspace-project-title {
            font-weight: 700;
            color: #fff;
            font-size: 0.95rem;
            margin-bottom: 0.35rem;
            word-break: break-word;
        }

        .workspace-project-meta {
            font-size: 0.75rem;
            color: var(--text-muted);
            margin-bottom: 0.75rem;
        }

        /* Universal Header Actions & Slide-out Drawer Styles across all screens */
        .desktop-nav-buttons {
            display: none !important;
        }
        .mobile-app-bar {
            display: flex;
            align-items: center;
            gap: 0.6rem;
        }
        #btn-mobile-drawer {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            border: 1px solid rgba(255, 255, 255, 0.2);
            background: rgba(15, 23, 42, 0.85);
            color: #fff;
            font-size: 1.25rem;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 0 4px 12px rgba(0,0,0,0.3);
            transition: all 0.2s ease;
        }
        #btn-mobile-drawer:hover {
            border-color: #00e5ff;
            background: rgba(30, 41, 59, 0.95);
        }
        #mobile-nav-drawer {
            position: fixed;
            top: 0;
            right: 0;
            width: 300px;
            height: 100vh;
            background: linear-gradient(160deg, rgba(15, 20, 38, 0.98), rgba(8, 10, 22, 0.99));
            backdrop-filter: blur(25px);
            z-index: 10000;
            border-left: 1px solid rgba(165, 180, 252, 0.25);
            box-shadow: -10px 0 40px rgba(0,0,0,0.85);
            transform: translateX(100%);
            transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            display: flex;
            flex-direction: column;
            padding: 1.5rem;
            box-sizing: border-box;
            overflow-y: auto;
        }
        #mobile-nav-drawer.active {
            transform: translateX(0);
        }
        #mobile-drawer-backdrop {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.65);
            backdrop-filter: blur(4px);
            z-index: 9999;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s ease;
        }
        #mobile-drawer-backdrop.active {
            opacity: 1;
            pointer-events: auto;
        }
        .mobile-drawer-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding-bottom: 1.2rem;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
            margin-bottom: 1.2rem;
        }
        .mobile-drawer-title {
            font-size: 1.1rem;
            font-weight: 800;
            background: linear-gradient(to right, #fff, #a5b4fc);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .mobile-drawer-close {
            background: none;
            border: none;
            color: #94a3b8;
            font-size: 1.7rem;
            cursor: pointer;
            line-height: 1;
            padding: 0 0.2rem;
        }
        .mobile-drawer-links {
            display: flex;
            flex-direction: column;
            gap: 0.85rem;
        }
        .mobile-drawer-links a, .mobile-drawer-links button {
            width: 100%;
            justify-content: flex-start !important;
            padding: 0 1.2rem !important;
        }

        /* Fixed Bottom Navigation Bar (Phase 2 Mobile & Universal Desktop Tab UX) */
        #mobile-bottom-nav {
            position: fixed;
            bottom: 0;
            left: 0;
            right: 0;
            height: 64px;
            background: rgba(15, 23, 42, 0.94);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-top: 1px solid rgba(255, 255, 255, 0.15);
            box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.5);
            z-index: 1500;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 0 0.75rem;
            gap: 0.75rem;
        }

        .mobile-bottom-tab {
            flex: 1;
            max-width: 220px;
            height: 48px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            background: transparent;
            border: none;
            color: var(--text-muted);
            border-radius: 12px;
            cursor: pointer;
            transition: all 0.2s ease;
            gap: 2px;
        }
        .mobile-bottom-tab.active {
            background: rgba(0, 229, 255, 0.12);
            color: #00e5ff;
            font-weight: 700;
        }
        .mobile-bottom-tab:hover {
            color: #fff;
        }
        .mobile-bottom-tab .tab-icon {
            font-size: 1.15rem;
            line-height: 1;
        }
        .mobile-bottom-tab .tab-label {
            font-size: 0.7rem;
            letter-spacing: 0.3px;
        }

        .mobile-bottom-generate {
            flex: 1.1;
            max-width: 240px;
            height: 44px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.4rem;
            background: linear-gradient(135deg, #00e5ff, #7c3aed);
            border: none;
            color: #fff;
            font-size: 0.82rem;
            font-weight: 700;
            border-radius: 24px;
            box-shadow: 0 4px 15px rgba(0, 229, 255, 0.35);
            cursor: pointer;
            transition: all 0.2s ease;
        }
        .mobile-bottom-generate:active {
            transform: scale(0.96);
        }

        /* Responsive Breakpoints */
        @media (max-width: 1180px) {
            header {
                padding: 0.75rem 1.25rem !important;
            }
            .desktop-nav-buttons {
                display: none !important;
            }
            .mobile-app-bar {
                display: flex !important;
            }
            h1 {
                font-size: 1.5rem !important;
            }
            .subtitle {
                font-size: 0.8rem !important;
            }

            /* Mobile Dual-Tab Workspace Layout */
            main {
                grid-template-columns: 1fr !important;
                padding-bottom: 64px !important;
            }
            .control-panel {
                border-right: none !important;
                width: 100% !important;
                display: flex !important;
            }
            .viewer-container {
                width: 100% !important;
                display: none !important;
            }
            main.mobile-view-preview .control-panel,
            main.mobile-view-workspace .control-panel {
                display: none !important;
            }
            main.mobile-view-preview .viewer-container {
                display: flex !important;
            }
            main.mobile-view-workspace .viewer-container {
                display: none !important;
            }
            main.mobile-view-workspace .workspace-panel {
                display: flex !important;
            }
            #mobile-bottom-nav {
                display: flex !important;
            }
            #download-btn {
                top: 4.5rem !important;
                right: 1.25rem !important;
                left: 1.25rem !important;
                justify-content: center !important;
            }
        }
        @media (max-width: 768px) {
            header {
                padding: 0.6rem 1rem !important;
            }
            .logo-container {
                gap: 0.6rem;
            }
            .logo-glow {
                width: 32px;
                height: 32px;
            }
        }