Are you talking about the leaves?

The Inspector shows that Firefox default to outset for the border-style property.

• https://developer.mozilla.org/en-US/docs/Web/CSS/border-style

The website would have to use "border-style:solid" to remove the beveling. ---

table:-moz-table-border-nonzero { 
  border-width: thin;
  border-style: outset;
}

That has worked for the bevel, but now there is still what looks like a drop shadow on the cells in the table, any ideas? http://andsotobed.co.uk/eshots/20-05-16/index.html

Actually, it's another bevel, this time a reversed bevel?

Maybe you like to collapse the borders.

• https://developer.mozilla.org/Web/CSS/border-collapse

border-collapse: collapse;

See also:

• https://developer.mozilla.org/en-US/Learn/CSS/Styling_boxes/Styling_tables