I'm trying to make a calculator in the tray using ElectronJS. The CSS code does not work in my application, but copy-and-pasting it into a JSFiddle, I see it works perfectly. When I look into the Dev Tools in my Electron App, it says that display: grid and its related properties are invalid. Does this have to do with Chromium's CSS grid support?
HTML Code
  <body>
    <div class="container">
      <div class="output-box"></div>
      <div class="buttons">
        <div class="button" id="7"><h3>7</h3></div>
        <div class="button" id="8">8</div>
        <div class="button" id="9">9</div>
        <div class="button" id="square">x^2</div>
        <div class="button" id="sqrt">sqrt</div>
        <div class="button" id="4">4</div>
        <div class="button" id="5">5</div>
        <div class="button" id="6">6</div>
        <div class="button" id="/">/</div>
        <div class="button" id="x">x</div>
        <div class="button" id="1">1</div>
        <div class="button" id="2">2</div>
        <div class="button" id="3">3</div>
        <div class="button" id="+">+</div>
        <div class="button" id="-">-</div>
        <div class="button" id="0">0</div>
        <div class="button" id=".">.</div>
        <div class="button" id="pi">pi</div>
        <div class="button" id="=">=</div>
      </div>
    </div>
  </body>
  <script src="renderer.js"></script>
CSS
.container {
  padding: 25px;
}
.output-box {
  width: 300px;
  height: 100px;
  border-radius: 5px;
  padding: 25px;
  border: 1px solid black;
}
.buttons {
  margin-top: 50px;
  height: 250px;
  width: 300px;
  padding: 25px;
  border-radius: 5px;
  border: 2px solid black;
  display: grid;
  grid-template-columns: repeat(5, 37.5px);
  grid-template-rows: repeat(4, 37.5px);
  gap: 12.5px 12.5px;
}


