CSS: border properties

In order to apply the border property to a <tr> element, the table's border-collapse property must be set to collapse.

See https://github.com/ReneNyffenegger/about-css/blob/master/properties/border/tr.html

border-spacing

border-collapse controls whether cells (<td> elements?) inside a <table> share their borders with the adjacent cell or if the borders are drawn separately.

border-radius

The margin and padding properties.

CSS properties

HTML elements: table, tr, td, thead, tbody