.fancy-border {
    border: 25px solid #000000;
    border-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='75' height='75'%3E%3Cg fill='none' stroke='%23000000' stroke-width='2'%3E%3Cpath d='M1 1h73v73H1z'/%3E%3Cpath d='M8 8h59v59H8z'/%3E%3Cpath d='M8 8h16v16H8zM51 8h16v16H51zM51 51h16v16H51zM8 51h16v16H8z'/%3E%3C/g%3E%3Cg fill='%23000000'%3E%3Ccircle cx='16' cy='16' r='2'/%3E%3Ccircle cx='59' cy='16' r='2'/%3E%3Ccircle cx='59' cy='59' r='2'/%3E%3Ccircle cx='16' cy='59' r='2'/%3E%3C/g%3E%3C/svg%3E") 25;
  }