:root { 
            --bg: #ffffff; --text: #1a1a1a; --accent: #006400; --border: #e0e0e0; --handle: #9EE400; --subtle: #8e8e93;
            --panel-bg: #ffffff; --ruler-bg: #fcfcfc; --stage-bg: #f5f5f7; --title-color: rgba(0, 50, 0, 0.1); --header-bg: rgba(255, 255, 255, 0.4);
            --btn-text: #ffffff; --keyframe-color: #1a1a1a;
            --bg-gray: #D9D9D9; --card-radius: 32px; --transition: all 0.2s ease-in-out;
            --anchor-color: #000000; --card-bg: #D9D9D9; --card-text: #000000;
        }
        [data-theme="dark"] {
            --bg: #121212; --text: #e0e0e0; --accent: #a6e22e; --border: #333333; --handle: #ffffff; --subtle: #888888;
            --panel-bg: #1e1e1e; --ruler-bg: #1a1a1a; --stage-bg: #000000; --title-color: rgba(166, 226, 46, 0.1); --header-bg: rgba(30, 30, 30, 0.4);
            --preview-title: rgba(166, 226, 46, 1);
            --btn-text: #1a1a1a; --keyframe-color: #ffffff;
            --anchor-color: #ffffff; --card-bg: #000000; --card-text: #ffffff;
        }
        * { box-sizing: border-box; }
        body { font-family: -apple-system, sans-serif; background: var(--bg); color: var(--text); margin: 0; padding: 0; display: flex; flex-direction: column; min-height: 100vh; overflow-y: scroll; }
        main { flex-grow: 1; display: flex; justify-content: center; align-items: center; }
        .container { width: 100%; max-width: 1800px; position: relative; padding: 0; display: flex; flex-direction: column; margin: 0 auto; }
        
        /* App Header */
        .app-header {
            display: flex; justify-content: space-between; align-items: center;
            width: 100%; padding: 30px 20px 15px;
            font-family: 'Sora', sans-serif;
        }
        .logo { font-family: 'Sora', sans-serif; font-weight: 700; font-size: 1.2rem; color: var(--text); letter-spacing: -0.02em; margin-left: 4px; }
        
        .hero-section { height: 100%; display: flex; flex-direction: column; justify-content: center; align-items: center; padding: 40px 20px; position: relative; }
        
        .hero-title { font-family: 'Sora', sans-serif; font-weight: 600; font-size: 3.5rem; margin: 0 0 20px 0; line-height: 1.1; color: var(--text); text-align: center; letter-spacing: -0.04em; max-width: 800px; margin-left: auto; margin-right: auto; }
        .header-description { text-align: center; color: var(--subtle); font-size: 0.95rem; line-height: 1.5; max-width: 600px; margin: 0 auto 30px auto; }
        .top-actions { padding-top: 5px; }
        
        .scroll-indicator {
            position: absolute; bottom: 50px; left: 50%;
            width: 12px; height: 12px;
            border-left: 2px solid var(--subtle);
            border-bottom: 2px solid var(--subtle);
            transform: translateX(-50%) rotate(-45deg);
            animation: bounce 2s infinite;
        }
        @keyframes bounce {
            0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) rotate(-45deg) translateY(0); }
            40% { transform: translateX(-50%) rotate(-45deg) translateY(-10px); }
            60% { transform: translateX(-50%) rotate(-45deg) translateY(-5px); }
        }

        .app-layer { position: relative; z-index: 10; background: transparent; height: 100%; display: flex; flex-direction: column; }

        .editor-wrapper { display: flex; align-items: stretch; flex: 1; min-height: 0; }
        .y-ruler-wrapper { position: relative; width: 40px; height: 100%; flex-shrink: 0; }
        .y-ruler { width: 100%; height: 100%; background: var(--ruler-bg); border-right: 1px solid var(--border); position: relative; overflow: hidden; }
        
        .y-ruler-controls {
            position: absolute; left: 45px; top: 10px; bottom: 10px;
            width: 32px; height: auto; transform: translateX(-10px);
            opacity: 0; pointer-events: none;
            transition: all 0.2s ease-in-out;
            z-index: 20;
            display: flex; flex-direction: column; align-items: center; gap: 0; padding: 0;
            background: var(--panel-bg); border: 1px solid var(--border);
            border-radius: 16px;
            font-size: 0.75rem; color: var(--subtle);
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            justify-content: center;
        }
        .y-ruler-controls::before {
            content: '';
            position: absolute;
            right: 100%;
            top: 0;
            bottom: 0;
            width: 30px;
        }
        .y-ruler-wrapper:hover .y-ruler-controls { opacity: 1; pointer-events: all; transform: translateX(0); }
        #y-zoom-slider { 
            flex: 1; cursor: pointer; accent-color: var(--text);
            writing-mode: vertical-lr; direction: rtl; width: 100%;
        }
        
        .y-tick { position: absolute; width: 100%; border-top: 1px solid #e0e0e0; font-size: 10px; color: var(--subtle); text-align: right; padding-right: 5px; box-sizing: border-box; }

        #canvas-container { 
            height: 100%; cursor: crosshair; background: var(--panel-bg); touch-action: none; flex: 1; position: relative; overflow: hidden; border: none;
        }
        canvas { width: 100%; height: 100%; display: block; }

        .timeline-container { display: flex; height: 34px; border-top: 1px solid var(--border); background: var(--ruler-bg); margin-bottom: 0; overflow: hidden; flex-shrink: 0; }
        .corner-spacer { width: 40px; flex-shrink: 0; border-right: 1px solid #e0e0e0; background: var(--ruler-bg); }
        .timeline-ruler { flex: 1; height: 100%; display: flex; position: relative; overflow: hidden; }
        .tick { position: absolute; height: 100%; border-left: 1px solid #e0e0e0; font-size: 10px; padding-left: 4px; color: var(--subtle); top: 0; display: flex; align-items: center; }

        .timeline-wrapper { position: relative; display: flex; flex-direction: column; }
        .timeline-wrapper:hover .timeline-controls { opacity: 1; pointer-events: all; transform: translateY(0); }

        .timeline-controls {
            position: absolute; bottom: 45px; left: 10px; right: 10px;
            opacity: 0; pointer-events: none; transform: translateY(10px);
            transition: all 0.2s ease-in-out;
            z-index: 20;
            display: flex; align-items: center; gap: 10px; padding: 4px 10px;
            background: var(--panel-bg); border: 1px solid var(--border); border-radius: 20px;
            font-size: 0.75rem; color: var(--subtle); height: 32px; flex-shrink: 0;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
            width: auto;
        }
        .timeline-controls::before {
            content: '';
            position: absolute;
            top: 100%;
            left: 0;
            right: 0;
            height: 30px;
        }
        .timeline-wrapper:hover .timeline-controls { opacity: 1; pointer-events: all; transform: translateY(0); }
        #zoom-slider { flex: 1; cursor: pointer; accent-color: var(--text); }

        .panel { padding: 20px 20px 20px 10px; background: var(--panel-bg); }
        .panel { flex: 1; min-width: 0; display: flex; flex-direction: column; height: 100%; padding: 0; }

        .code-mask {
            flex: 1; background: #1a1a1a; border: none; overflow: hidden; position: relative; display: flex; min-width: 0;
        }

        #css-output { 
            background: transparent; color: #a6e22e; padding: 20px; border-radius: 0; font-size: 0.85rem; 
            overflow: auto; margin: 0; line-height: 1.5; border: none; flex: 1;
            scrollbar-color: #444 #1a1a1a;
            width: 100%; height: 100%;
            font-family: 'Menlo', 'Monaco', 'Courier New', monospace; outline: none;
            white-space: pre;
        }
        #css-output::-webkit-scrollbar { width: 10px; height: 10px; }
        #css-output::-webkit-scrollbar-track { background: #1a1a1a; }
        #css-output::-webkit-scrollbar-thumb { background: #444; border-radius: 8px; border: 2px solid #1a1a1a; }
        #css-output::-webkit-scrollbar-corner { background: #1a1a1a; }
        
        .editable { color: #ccff00; font-weight: 700; border-bottom: 1px dashed #666; cursor: text; display: inline-block; min-width: 10px; text-align: center; }
        .editable:focus { border-bottom: 1px solid #fff; background: rgba(255,255,255,0.1); outline: none; }
        [contenteditable="false"] { opacity: 0.7; cursor: default; }
        
        button { background: var(--text); color: var(--btn-text); border: none; padding: 10px 20px; border-radius: 6px; cursor: pointer; font-weight: 600; font-size: 0.85rem; transition: all 0.2s; }
        button:hover { opacity: 0.85; transform: translateY(-1px); }
        button.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }
        button.secondary:hover { background: var(--text); color: var(--bg); border-color: var(--text); opacity: 1; }
        button.accent { background: var(--accent); color: var(--btn-text); }
        #presets-btn { background: transparent; border: none; color: var(--text); }
        #presets-btn:hover { background: transparent; color: var(--text); transform: scale(1.1); opacity: 1; }
        
        .bottom-section { display: flex; align-items: stretch; height: 100%; border: none; overflow: hidden; position: relative; }
        .preview-box { flex: 1; padding: 0; background: var(--panel-bg); display: flex; flex-direction: column; height: 100%; }
        
        .preview-stage { flex: 1; background: #D7D7D7; border-radius: 0; position: relative; overflow: hidden; perspective: 1000px; }
        .preview-controls { position: absolute; top: 20px; left: 20px; z-index: 10; display: flex; gap: 8px; }
        .preview-ball { width: 160px; height: 160px; background: url("data:image/svg+xml,%3Csvg width='232' height='232' viewBox='0 0 232 232' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Crect x='1' y='1' width='230' height='230' rx='39' fill='%23C1C1C1' stroke='%23505050' stroke-width='2' stroke-dasharray='6 6'/%3E%3C/svg%3E") no-repeat center center; background-size: contain; border-radius: 0; position: absolute; top: 50%; margin-top: -80px; left: 50%; margin-left: -80px; }
        .preview-ball.centered-mode { top: 50%; left: 50%; margin: -80px 0 0 -80px; }
        select { padding: 8px 12px; border-radius: 6px; border: 1px solid var(--border); font-size: 0.9rem; }
        .preview-controls select {
            background: var(--bg);
            color: var(--text);
            border: 1px solid var(--border);
            font-size: 0.75rem;
            padding: 8px 12px;
            font-weight: 600;
            cursor: pointer;
        }
        .preview-controls select:hover { border-color: var(--text); }
        .preview-controls button {
            background: var(--bg);
            color: var(--text);
            border: 1px solid var(--border);
            font-size: 0.75rem;
            padding: 8px 12px;
            font-weight: 600;
            cursor: pointer;
            border-radius: 6px;
        }
        .preview-controls button:hover { border-color: var(--text); transform: none; opacity: 1; }
        .preview-controls button.active {
            border-color: var(--accent);
            color: var(--accent);
        }
        #anchor-indicator {
            position: absolute;
            width: 10px; height: 10px;
            background: #007aff;
            border-radius: 50%;
            border: 2px solid white;
            box-shadow: 0 0 5px rgba(0,0,0,0.5);
            transform: translate(-50%, -50%);
            display: none;
            pointer-events: none; z-index: 1;
        }
        .panel { flex: 1; min-width: 0; display: flex; flex-direction: column; }
        
        /* Custom Dropdown Styles */
        .custom-dropdown { position: relative; display: inline-flex; align-items: center; gap: 8px; }
        .mode-display {
            background: var(--bg);
            color: var(--text);
            border: 1px solid var(--border);
            font-size: 0.75rem;
            padding: 8px 12px;
            font-weight: 600;
            border-radius: 6px;
            font-family: 'Inter', sans-serif;
            user-select: none;
        }
        .dropdown-trigger {
            background: var(--bg);
            color: var(--text);
            border: 1px solid var(--border);
            width: 32px; height: 32px;
            padding: 0;
            cursor: pointer;
            display: flex; align-items: center; justify-content: center;
            border-radius: 50%;
            transition: all 0.2s;
        }
        .dropdown-trigger:hover { border-color: var(--text); transform: none; opacity: 1; }
        .dropdown-trigger svg { opacity: 0.6; }
        
        .dropdown-menu {
            display: none; position: absolute; top: 100%; left: 0; margin-top: 4px;
            background: var(--panel-bg); border: 1px solid var(--border); border-radius: 8px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.15); z-index: 1000; min-width: 160px;
            overflow: hidden; padding: 4px;
        }
        .dropdown-menu.show { display: block; animation: scaleIn 0.1s ease-out; }
        .dropdown-item { padding: 8px 12px; font-size: 0.75rem; cursor: pointer; color: var(--text); font-family: 'Inter', sans-serif; border-radius: 4px; transition: background 0.1s; text-transform: none; font-weight: 600; }
        .dropdown-item:hover { background: var(--bg-gray); }
        .dropdown-item.selected { background: var(--text); color: var(--bg); }
        [data-theme="dark"] .dropdown-item:hover { background: #333; }

        #multi-mode-btn { background: var(--bg); margin-left: 8px; text-transform: uppercase; }
        #multi-mode-btn, #anim-mode { font-family: 'Menlo', 'Monaco', 'Courier New', monospace; }
        #multi-mode-btn.active { background: var(--text); color: var(--bg); }
        #multi-mode-btn:hover { background: #D7D7D7; color: #000000; border-color: transparent; }
        
        #anim-mode {
            background: var(--bg);
            color: var(--text);
            border: 1px solid var(--border);
            font-size: 0.75rem;
            padding: 8px 12px;
            font-weight: 600;
            cursor: pointer;
            text-transform: none;
        }

        
        @media (max-width: 950px) {
            .container { display: flex; flex-direction: column; }
            .hero-title { font-size: 2.25rem; }  
            .header-description { order: 2; margin-bottom: 30px; font-size: 0.75rem; }
            .big-footer { order: 5; }
            .bottom-section { flex-direction: column; height: auto; }
            .preview-box { padding: 0; }
            .preview-box { border-bottom: 1px solid var(--border); }
            .preview-ball { width: 30px; height: 30px; margin-top: -15px; margin-left: -15px; }
            .panels-container { max-width: 600px; margin: 0 auto; }
            #hotkeys-toggle-btn { display: none; }
        }

        .overlay-btn { position: absolute; z-index: 10; font-size: 0.75rem; padding: 8px 12px; }
        .overlay-btn.top-right { top: 15px; right: 15px; }
        .overlay-btn.bottom-right { bottom: 15px; right: 15px; }
        .overlay-label { font-size: 0.75rem; padding: 8px 12px; color: var(--text); pointer-events: none; font-weight: 600; }

        @keyframes pop {
            0% { transform: scale(1); }
            50% { transform: scale(1.01); }
            100% { transform: scale(1); }
        }
        
        @keyframes scaleIn {
            from { transform: scale(0.9); }
            to { transform: scale(1); }
        }
        
        .pop { animation: pop 0.3s ease-out; z-index: 10; }
        
        .big-footer {
            width: 100%; background: var(--bg); color: var(--text); min-height: auto; padding: 60px 0;
            display: flex; justify-content: center;
            margin-top: 60px;
            position: relative;
        }
        .footer-content {
            width: 100%; max-width: 1800px;
            display: flex; flex-direction: column; justify-content: space-between;
            margin: 0 auto; padding: 0 20px;
            position: relative;
        }
        .footer-content::before {
            content: ''; position: absolute; top: -60px; left: 20px; right: 20px;
            height: 1px; background: var(--border);
        }
        .footer-bottom-row {
            display: flex; align-items: center; justify-content: space-between; width: 100%;
        }
        .header-actions, .footer-actions { display: flex; align-items: center; gap: 12px; }
        .theme-toggle-header {
            background: transparent; border: 1px solid var(--border); color: var(--text);
            width: 36px; height: 36px; padding: 0; border-radius: 50%;
            display: flex; align-items: center; justify-content: center; cursor: pointer;
            transition: all 0.2s;
        }
        .theme-toggle-header:hover { border-color: var(--text); transform: translateY(-1px); }
        .theme-toggle-header svg { width: 18px; height: 18px; }
        .footer-brand {
            font-family: 'Inter', sans-serif;
            font-weight: 600;
            font-size: 1.2rem;
            color: var(--text);
            text-decoration: none;
            transition: color 0.2s;
        }
        .footer-brand:hover { color: var(--subtle); }
        .footer-brand .made-by {
            color: var(--subtle);
        }

        .code-controls {
            position: absolute; top: 10px; right: 10px; z-index: 10;
            display: flex; gap: 6px;
        }
        .code-toggle {
            background: #333; color: #ccc; border: 1px solid #444;
            font-size: 0.75rem; padding: 4px 8px; border-radius: 4px;
            outline: none; cursor: pointer; -webkit-appearance: none;
        }
        .code-toggle:hover { color: #fff; border-color: #666; }
        
        .theme-icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
        [data-theme="dark"] .icon-moon { display: none; }
        [data-theme="dark"] .icon-sun { display: block; }
        body:not([data-theme="dark"]) .icon-sun { display: none; }
        body:not([data-theme="dark"]) .icon-moon { display: block; }
        
        .preview-button {
            width: 100px; height: 40px; 
            background: var(--accent); color: var(--btn-text); 
            border: none; border-radius: 6px; font-weight: 600;
            position: absolute; top: 50%; margin-top: -20px; left: 50%; margin-left: -50px;
            display: none; align-items: center; justify-content: center; cursor: pointer;
        }
        .preview-button:hover { opacity: 1; transform: none; cursor: default; }
        
        /* Presets Section */
        .presets-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 20px; padding: 20px 10px 10px 10px; }
        .preset-card { background: var(--panel-bg); border: 1px solid var(--border); border-radius: 10px; padding: 12px; cursor: pointer; transition: 0.2s; position: relative; }
        .preset-card:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: 0 10px 20px rgba(0,0,0,0.05); z-index: 10; }
        
        .preset-visuals { display: flex; gap: 8px; height: 100px; width: 100%; margin-bottom: 0; }
        .preset-thumb { flex: 1; height: 100%; background: var(--stage-bg); border-radius: 6px; width: 0; display: block; pointer-events: none; }
        .preset-preview-box { flex: 1; height: 100%; background: var(--stage-bg); border-radius: 6px; position: relative; overflow: hidden; width: 0; }
        .preset-preview-ball { 
            width: 40px; height: 40px; 
            position: absolute; top: 50%; left: 50%; margin-top: -20px; margin-left: -20px; 
            background-size: contain; background-repeat: no-repeat; background-position: center; 
            border-radius: 50%; 
            background-image: url("data:image/svg+xml,%3Csvg width='232' height='232' viewBox='0 0 232 232' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Crect x='1' y='1' width='230' height='230' rx='39' fill='%23C1C1C1' stroke='%23505050' stroke-width='2' stroke-dasharray='6 6'/%3E%3C/svg%3E");
        }
        
        .preset-title { font-weight: 600; font-size: 0.85rem; color: var(--text); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; margin-bottom: 10px; }
        .preset-title[contenteditable]:focus { outline: 1px solid var(--accent); background: var(--bg); cursor: text; overflow: visible; white-space: normal; z-index: 10; position: relative; }
        .preset-delete-btn {
            position: absolute; top: 8px; right: 8px; width: 22px; height: 22px;
            background: var(--text); color: var(--bg); border: none; border-radius: 50%;
            display: flex; align-items: center; justify-content: center;
            cursor: pointer; opacity: 0; transition: 0.2s;
        }
        .preset-card:hover .preset-delete-btn { opacity: 1; }
        .preset-delete-btn:hover { opacity: 0.8; }
        .preset-share-btn {
            position: absolute; top: 8px; right: 38px; width: 22px; height: 22px;
            background: var(--text); color: var(--bg); border: none; border-radius: 50%;
            display: flex; align-items: center; justify-content: center;
            cursor: pointer; opacity: 0; transition: 0.2s;
        }
        .preset-card:hover .preset-share-btn { opacity: 1; }
        .preset-share-btn:hover { opacity: 0.8; }
        
        /* Presets Popup */
        .presets-popup {
            position: fixed; top: 0; left: 0; width: 100%; height: 100%;
            background: rgba(0,0,0,0.5); z-index: 1000;
            display: flex; justify-content: center; align-items: center;
            opacity: 0; pointer-events: none; transition: opacity 0.2s;
            backdrop-filter: blur(5px);
        }
        .presets-popup.active { opacity: 1; pointer-events: all; }
        .popup-content {
            background: var(--panel-bg); width: 90%; max-width: 800px; max-height: 85vh;
            border-radius: 16px; padding: 30px; display: flex; flex-direction: column; gap: 20px;
            box-shadow: 0 20px 50px rgba(0,0,0,0.3); border: 1px solid var(--border);
        }
        .popup-header { display: flex; justify-content: space-between; align-items: center; }
        .popup-header h2 { margin: 0; font-family: 'Sora', sans-serif; font-weight: 700; letter-spacing: -0.02em; font-size: 1.5rem; color: var(--text); }
        .close-btn { background: transparent; color: var(--text); padding: 0; cursor: pointer; border: none; display: flex; align-items: center; justify-content: center; width: 40px; height: 40px; border-radius: 50%; transition: background 0.2s; }
        .close-btn:hover { background: rgba(0,0,0,0.05); transform: none; opacity: 1; }
        .popup-auth { display: flex; align-items: center; gap: 10px; margin-left: auto; }
        .user-pill { display: flex; align-items: center; gap: 8px; font-weight: 600; font-size: 0.85rem; }
        .user-pill img { width: 28px; height: 28px; border-radius: 50%; border: 1px solid var(--border); }
        .popup-actions { display: flex; gap: 15px; }
        .presets-grid-scroll { overflow-y: auto; flex: 1; min-height: 200px; padding-right: 5px; }

        /* Hotkeys Popup */
        .hotkeys-list { display: grid; grid-template-columns: 1fr; gap: 12px; }
        .hotkey-item { display: flex; justify-content: space-between; align-items: center; padding: 8px 0; border-bottom: 1px solid var(--border); }
        .hotkey-item:last-child { border-bottom: none; }
        .hotkey-keys { display: flex; gap: 4px; }
        .kbd { 
            background: var(--bg-gray); 
            border: 1px solid var(--border); 
            border-radius: 4px; 
            padding: 2px 6px; 
            font-family: monospace; 
            font-size: 0.75rem; 
            font-weight: 600; 
            color: var(--text);
        }

        .hidden { display: none !important; }

        /* New Panel System */
        .panels-container {
            display: flex; flex-direction: column; height: auto; width: 100%;
            padding: 0 20px 20px;
            gap: 8px;
        }
        .panel-section {
            display: flex; flex-direction: column;
            border: 2px solid var(--border);
            background: var(--panel-bg);
            transition: all 0.25s cubic-bezier(0.01, 0.68, 0.1, 1);
            overflow: hidden;
            box-shadow: 0 4px 20px rgba(0,0,0,0.08);
            width: 100%;
            position: relative;
            backface-visibility: hidden;
            border-radius: 12px;
        }
        .panel-section.open { border-radius: 12px; flex: 1 0 auto; align-self: flex-start; min-width: 0; min-height: 0; aspect-ratio: 1 / 1; }
        .panel-section.closed { height: 60px; min-height: 60px; border-radius: 50px; cursor: pointer; flex-shrink: 0; }
        @media (hover: hover) {
            .panel-section.closed:hover { border-color: var(--text); background: var(--text); }
            .panel-section.closed:hover .panel-header { color: var(--panel-bg); }
        }
        
        .panel-header {
            height: 60px; min-height: 60px;
            display: flex; align-items: center; justify-content: flex-start;
            padding: 0 16px;
            gap: 12px;
            background: var(--ruler-bg);
            border-bottom: 1px solid var(--border);
            cursor: pointer;
            font-family: 'Inter', sans-serif; font-weight: 600; font-size: 0.85rem;
            color: var(--text);
            user-select: none;
            white-space: nowrap;
            overflow: hidden;
        }
        @media (hover: hover) {
            .panel-header:hover { background: var(--stage-bg); }
        }
        .panel-section.closed .panel-header { border-bottom: none; background: transparent; }
        
        .panel-content {
            flex: 1;
            overflow: hidden;
            position: relative;
            display: flex; flex-direction: column;
            opacity: 1; transition: opacity 0.25s;
            min-height: 0;
        }
        .panel-section.closed .panel-content { opacity: 0; pointer-events: none; }
        
        .panel-section.opening {
            /* Override 'all' to prevent background/color from transitioning on open */
            transition-property: flex, min-width, width, height, border-radius;
        }
        
        #panel-overview .panel-content { overflow-y: auto; display: flex; flex-direction: column; }
        
        #panel-overview .hero-section {
            align-items: flex-start;
            justify-content: flex-start;
            height: auto;
            flex-grow: 1;
        }
        #panel-overview .hero-title,
        #panel-overview .header-description {
            text-align: left;
            margin-left: 0;
        }
        .panel-inner {
            display: flex; flex-direction: column;
            position: absolute; top: 0; left: 0; right: 0; bottom: 0;
        }

        @media (min-width: 951px) {
            .panels-container { 
                display: grid; 
                grid-template-columns: 1fr 1fr 60px 60px; 
                align-items: stretch; 
                height: auto; 
                min-height: 320px; 
                transition: grid-template-columns 0.5s cubic-bezier(0.03, 0.47, 0.04, 1.00);
            }
            .panel-section { width: auto; }
            .panel-section.open { aspect-ratio: 1 / 1; min-width: 320px; min-height: 320px; }
            .panel-section.closed { height: auto; min-height: 0; padding: 0; border-radius: 12px; }
            .panel-section.closed .panel-header {
                writing-mode: vertical-rl;
                text-orientation: mixed;
                transform: rotate(180deg);
                width: 100%; height: 100%;
                justify-content: center; padding: 0;
                opacity: 0;
                animation: headerFadeIn 0.4s ease-out forwards 0.1s;
            }
            @keyframes headerFadeIn {
                to { opacity: 1; }
            }
            @keyframes panelEnter {
                0% { transform: scale(0.95); opacity: 0; filter: brightness(1.5); }
                100% { transform: scale(1); opacity: 1; filter: brightness(1); }
            }
            .panel-section.panel-enter .panel-inner {
                animation: panelEnter 0.5s cubic-bezier(0.03, 0.47, 0.04, 1.00) forwards;
            }
            .panel-section.white-out {
                opacity: 0;
                visibility: hidden;
                transition: none;
            }
            .panel-section.closing .panel-inner {
                opacity: 0;
                visibility: hidden;
            }
        }

        @media (max-width: 950px) {
            .panel-inner { position: relative; }
            .panel-section.open { aspect-ratio: auto; }
            #panel-overview.open { height: auto; }
            #canvas-container { height: auto; aspect-ratio: 3 / 4; }
            .preview-stage { height: auto; aspect-ratio: 3 / 4; }
            .panel-content, .editor-wrapper, .preview-box { height: auto; }
            #panel-code .panel-content { aspect-ratio: 3 / 4; width: 100%; flex: none; }
            .y-ruler-wrapper { height: auto; }
            .popup-header h2 { font-size: 0.85rem; }
        }
        
        .header-actions button {
            height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }
        #share-btn { background: #000000; color: #ffffff; border: 1px solid transparent; }
        #share-btn:hover { background: #D7D7D7; color: #000000; opacity: 1; }
        #popup-save-btn { background: #000000; color: #ffffff; border: 1px solid transparent; }
        #popup-save-btn:hover { background: #D7D7D7; color: #000000; opacity: 1; }

        /* Overview Cards */
        .overview-cards-container { display: flex; gap: 10px; align-items: flex-end; padding: 20px 20px 40px 20px; margin-top: auto; flex-wrap: wrap; }
        .card {
            background-color: var(--card-bg);
            width: 192px; height: 192px;
            border-radius: var(--card-radius);
            padding: 10px 10px 26px 10px;
            display: flex; flex-direction: column; justify-content: space-between;
            box-sizing: border-box; cursor: pointer; transition: var(--transition);
            text-decoration: none; color: var(--card-text);
        }
        .card:hover { transform: translateY(-4px); filter: brightness(0.95); }
        .card-top { display: flex; align-items: flex-start; }
        .card-bottom { display: flex; flex-direction: column; gap: 10px; }
        .card-title {
            font-size: 19px; line-height: 1.1; font-weight: 500; margin: 0;
            max-width: 112px; letter-spacing: -0.02em; color: var(--card-text);
        }
        .share-btn-round {
            background-color: black;
            width: 53px; height: 53px;
            border-radius: 50%;
            display: flex; justify-content: center; align-items: center;
            border: none; cursor: pointer; transition: var(--transition);
            margin-bottom: 0;
        }
        [data-theme="dark"] .share-btn-round { background-color: #333333; }
        .share-btn-round:hover { transform: scale(1.1); background-color: #333; }
        .icon-main { width: 40px; height: 40px; }
        .icon-arrow { width: 12px; height: auto; }

        @media (max-width: 950px) {
            /* Mobile Overview Cards: Horizontal Scroll */
            .overview-cards-container { display: flex; flex-direction: row; flex-wrap: nowrap !important; overflow-x: auto; justify-content: flex-start; -webkit-overflow-scrolling: touch; width: 100%; }
            .overview-cards-container::-webkit-scrollbar { display: none; }
            .card, .share-btn-round { flex-shrink: 0; }
            
            /* Ensure Share button fits text on one line */
            #share-btn { white-space: nowrap; padding-left: 24px; padding-right: 24px; }

            /* Presets Mobile Fixes */
            .presets-grid { grid-template-columns: 1fr; padding: 0; }
            .presets-grid-scroll { padding-right: 0; }
            .popup-actions button { flex: 1; }
            .popup-content { padding: 20px; width: 95%; }
        }

        /* Auth Styles */
        #auth-popup { z-index: 1100; }
        .auth-input {
            width: 100%; padding: 12px; margin-bottom: 10px;
            background: var(--bg); border: 1px solid var(--border);
            border-radius: 8px; color: var(--text); font-size: 0.9rem;
        }
        .auth-input:focus { outline: none; border-color: var(--accent); }
        .auth-divider {
            text-align: center; margin: 15px 0; color: var(--subtle); font-size: 0.8rem; position: relative;
        }
        .auth-divider::before, .auth-divider::after {
            content: ''; position: absolute; top: 50%; width: 45%; height: 1px; background: var(--border);
        }
        .auth-divider::before { left: 0; }
        .auth-divider::after { right: 0; }
        .auth-switch {
            text-align: center; font-size: 0.85rem; color: var(--subtle); margin-top: 15px;
        }
        .auth-switch a { color: var(--text); text-decoration: underline; cursor: pointer; }
        #auth-submit-btn { background: #000000; color: #ffffff; border: 1px solid transparent; }
        #auth-submit-btn:hover { background: #D7D7D7; color: #000000; opacity: 1; }

        /* Login message */
        .login-message {
            text-align: center; color: var(--subtle); font-size: 0.95rem; margin: 15px auto 5px auto; line-height: 1.5; max-width: 500px;
        }

        /* Feedback button */
        .feedback-btn {
            text-decoration: none; color: var(--subtle); font-size: 0.9rem; font-weight: 500;
            display: flex; align-items: center; justify-content: center;
            transition: color 0.2s;
            font-family: 'Inter', sans-serif;
        }
        .feedback-btn:hover { color: var(--text); }
        .feedback-icon { display: none; }

        @media (max-width: 950px) {
            .feedback-text { display: none; }
            .feedback-icon { display: block; width: 18px; height: 18px; }
            .feedback-btn {
                background: transparent; border: 1px solid var(--border); color: var(--text);
                width: 36px; height: 36px; padding: 0; border-radius: 50%;
            }
            .feedback-btn:hover { border-color: var(--text); transform: translateY(-1px); }
        }