body{margin:0;display:flex;height:100vh;overflow:hidden}#canvas-container{position:relative;flex-grow:1}#image-canvas,#box-canvas{position:absolute;top:0;left:0}#tool-pane{width:300px;background-color:lightgray;padding:20px;box-sizing:border-box}#delete-btn,#confirm-btn{margin-top:10px;padding:5px 10px;background-color:red;color:white;border:0;cursor:pointer}#confirm-btn{background-color:blue}#controls{margin-top:10px}