body, html {
            margin: 0;
            padding: 0;
            width: 100%;
            height: 100%;
            overflow: hidden;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: #333;
        }

        #scene {
            display: block;
            width: 100%;
            height: 100%;
            transform: translateZ(0);
        }

        /* Show Button */
        #show-btn {
            position: absolute;
            bottom: 20px;
            right: 20px;
            width: 50px;
            height: 50px;
            background: rgba(20, 20, 20, 0.9);
            color: white;
            border-radius: 50%;
            border: 1px solid rgba(255,255,255,0.2);
            cursor: pointer;
            display: flex; 
            align-items: center;
            justify-content: center;
            font-size: 24px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.5);
            transition: transform 0.2s;
            z-index: 90;
        }
        #show-btn:hover {
            transform: scale(1.1);
            background: #444;
        }

        /* Panel */
        #controls {
            position: absolute;
            bottom: 20px;
            right: 20px;
            width: 320px;
            background: rgba(20, 20, 20, 0.9);
            color: #eee;
            padding: 20px;
            border-radius: 12px;
            box-shadow: 0 8px 32px rgba(0,0,0,0.6);
            backdrop-filter: blur(8px);
            display: flex;
            flex-direction: column;
            gap: 12px;
            max-height: 90vh;
            overflow-y: auto;
            border: 1px solid rgba(255,255,255,0.1);
            z-index: 100;
            transition: opacity 0.3s, transform 0.3s;
        }

        #controls.hidden {
            opacity: 0;
            transform: translateY(20px);
            pointer-events: none;
        }

        .panel-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            border-bottom: 1px solid #444;
            padding-bottom: 8px;
            margin-bottom: 5px;
        }

        .panel-header h3 {
            margin: 0;
            font-size: 16px;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        #hide-btn {
            background: none;
            border: 1px solid #555;
            color: #aaa;
            border-radius: 4px;
            padding: 2px 8px;
            font-size: 11px;
            cursor: pointer;
        }
        #hide-btn:hover {
            background: #444;
            color: white;
        }

        #controls::-webkit-scrollbar { width: 6px; }
        #controls::-webkit-scrollbar-thumb { background-color: #555; border-radius: 3px; }

        .control-group { display: flex; flex-direction: column; gap: 6px; }
        .row { display: flex; justify-content: space-between; align-items: center; }
        
        label { font-size: 13px; font-weight: 600; color: #ccc; }
        span.val { font-family: monospace; color: #4db8ff; font-size: 12px; }

        input[type="range"] { width: 100%; cursor: pointer; accent-color: #4db8ff; }
        input[type="file"] { font-size: 12px; color: #bbb; }
        input[type="file"]::file-selector-button {
            background: #444; color: white; border: none; padding: 5px 10px;
            border-radius: 4px; cursor: pointer; margin-right: 10px;
        }
        input[type="color"] { width: 100%; height: 30px; border: none; border-radius: 4px; cursor: pointer; background: none; }

        .divider { height: 1px; background: #444; margin: 5px 0; }
        
        /* Highlight new control */
        .highlight label { color: #ffeb3b; }