*{box-sizing:border-box;margin:0;padding:0}html,body{font-family:Helvetica Neue,Arial,sans-serif;background-color:#f0f0f0;height:100%;overflow:hidden}#app-container{display:flex;width:100vw;height:100vh}#viewer-container{flex-grow:1;position:relative;background-color:#e0e0e0}#viewer-canvas{display:block;width:100%;height:100%}#controls{width:300px;flex-shrink:0;padding:1.5rem;background-color:#fff;box-shadow:-2px 0 5px #0000001a;overflow-y:auto;display:flex;flex-direction:column;gap:1rem}h1{font-size:1.8rem;color:#333;text-align:center;margin-bottom:1rem}.control-group{display:flex;flex-direction:column;gap:.5rem}label{font-weight:700;color:#555}select,button{padding:.6rem;border:1px solid #ccc;border-radius:4px;font-size:1rem}select{width:100%}button{cursor:pointer;background-color:#007bff;color:#fff;border:none;transition:background-color .2s ease}button:hover:not(:disabled){background-color:#0056b3}button:disabled{background-color:#ccc;cursor:not-allowed}.status{margin-top:1rem;font-size:.9rem;color:#666}.error{color:#dc3545;font-weight:700}