.threed-container{display:flex;gap:12px;font-family:Arial,Helvetica,sans-serif}
.left-panel{width:320px;padding:12px;border-right:1px solid #eee;background:#fafafa}
.viewer{flex:1;height:600px;background:#333}
.left-panel input, .left-panel button, .left-panel select{width:100%;margin:6px 0;padding:8px}
.export-btn{margin:6px 4px 0 0;padding:6px 12px}