popup.html

<!DOCTYPE html>

<html>
  <head>
    <meta charset="utf-8" />
    <style>
      body {
        margin: 8px 8px;
      }

      .item {
        white-space: nowrap;
        text-align: center;

        width: auto;
        padding: 8px;

        margin: 0;
        margin-top: 8px;

        background-color: transparent;
      }

      .button {
        display: block;

        font-size: small;
        text-decoration: none;
        color: white;

        background-color: #ac88ff;

        outline: none;

        border: 1px solid #0047ab;
        border-radius: 4px;
      }

      .button:focus {
        box-shadow: 0 0 0 1px #0047ab;
      }

      #title {
        font-size: medium;

        border: 2px solid #0047ab;
        border-radius: 8px;
      }
    </style>
  </head>

  <body>
    <h1 class="item" id="title">GeForce NOW Unlocker</h1>
    <a href="https://github.com/murar8/gfn-unlocker" target="_blank" class="item button"> Open the project's website</a>
    <a href="https://github.com/murar8/gfn-unlocker/issues" target="_blank" class="item button">Report an issue</a>
    <a
      href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=WW7VLKVE9YP8Q&source=url"
      target="_blank"
      class="item button"
      >Make a donation</a
    >
  </body>
</html>