video-pc/resources/window-bar/maximize.svg

<svg id="图层_1" data-name="图层 1" xmlns="http://www.w3.org/2000/svg" width="10" height="10" viewBox="0 0 10 10">
  <defs>
    <style>
      .cls-1 {
        fill: none;
        stroke: white;
        stroke-miterlimit: 10;
      }
    </style>
  </defs>
  <rect class="cls-1" x="0.5" y="0.5" width="9" height="9" />
</svg>