* { box-sizing: border-box; }
    body {
      font-family: Arial, sans-serif;
      margin: 20px;
      user-select: none;
      background: #f5f5f5;
    }

    h2 {
      margin-top: 0;
      color: #333;
    }

    .section {
      background: white;
      padding: 20px;
      margin-bottom: 20px;
      border-radius: 8px;
      box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }

    .controls {
      margin: 15px 0;
      display: flex;
      gap: 10px;
      flex-wrap: wrap;
    }

    button {
      padding: 10px 20px;
      background: #007bff;
      color: white;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 14px;
    }
    button:hover {
      background: #0056b3;
    }
    button:active {
      transform: translateY(1px);
    }

    #container {
      position: relative;
      display: inline-block;
      border: 2px solid #333;
      background: repeating-conic-gradient(#eee 0% 25%, #fff 0% 50%) 50% / 20px 20px;
      user-select: none;
      line-height: 0;
    }

    #main-image {
      display: block;
      pointer-events: none;
      image-rendering: optimizeSpeed !important;
      image-rendering: -moz-crisp-edges !important;
      image-rendering: -webkit-optimize-contrast !important;
      image-rendering: pixelated !important;
    }

    .widget {
      position: absolute;
      border: 1px solid #c00;
      background: rgba(255,0,0,.15);
      cursor: move;
    }

    .widget.dragging {
      opacity: 0.6;
      cursor: grabbing;
    }

    .widget.selected {
      border-color: #f0f;
      box-shadow: 0 0 0 2px #f0f;
    }

    .inner {
      position: absolute;
      border: 1px solid #00c;
      background: rgba(0,0,255,.15);
      cursor: move;
      pointer-events: auto;
    }

    .inner.dragging {
      opacity: 0.6;
      cursor: grabbing;
    }

    .resize-handle {
      position: absolute;
      width: 10px;
      height: 10px;
      background: #fff;
      border: 1px solid;
      z-index: 10;
      pointer-events: auto;
    }

    .widget > .resize-handle {
      border-color: #c00;
      background: #fcc;
    }

    .inner > .resize-handle {
      border-color: #00c;
      background: #ccf;
    }

    .resize-handle.nw { top: -5px; left: -5px; cursor: nw-resize; }
    .resize-handle.ne { top: -5px; right: -5px; cursor: ne-resize; }
    .resize-handle.sw { bottom: -5px; left: -5px; cursor: sw-resize; }
    .resize-handle.se { bottom: -5px; right: -5px; cursor: se-resize; }
    .resize-handle.n { top: -5px; left: 50%; margin-left: -5px; cursor: n-resize; }
    .resize-handle.s { bottom: -5px; left: 50%; margin-left: -5px; cursor: s-resize; }
    .resize-handle.w { top: 50%; margin-top: -5px; left: -5px; cursor: w-resize; }
    .resize-handle.e { top: 50%; margin-top: -5px; right: -5px; cursor: e-resize; }

    .widget-label {
      position: absolute;
      top: -25px;
      left: 0;
      background: #c00;
      color: white;
      padding: 2px 8px;
      font-size: 11px;
      border-radius: 3px;
      pointer-events: none;
      white-space: nowrap;
    }

    .info-box {
      background: #e3f2fd;
      border-left: 4px solid #2196f3;
      padding: 12px;
      margin: 15px 0;
      font-size: 14px;
      line-height: 1.5;
    }

    #spritesheet-container {
      margin-top: 20px;
      border: 2px solid #333;
      background: repeating-conic-gradient(#eee 0% 25%, #fff 0% 50%) 50% / 20px 20px;
      display: inline-block;
      padding: 10px;
    }

    #spritesheet {
      display: block;
      image-rendering: pixelated;
      image-rendering: crisp-edges;
      max-width: 100%;
    }

    #output {
      margin-top: 15px;
      white-space: pre-wrap;
      background: #fafafa;
      padding: 15px;
      border: 1px solid #ddd;
      border-radius: 4px;
      font-family: 'Courier New', monospace;
      font-size: 12px;
      max-height: 400px;
      overflow-y: auto;
    }