Horizontal lines on table not showing when exporting to HTML

Question

I have this table,

|   A |   B |   C |
|-----+-----+-----|
| 123 | 123 | 123 |
|-----+-----+-----|
|   4 |   5 |   5 |
|-----+-----+-----|
|   3 |   2 |   1 |
|-----+-----+-----|
|     |     |     |

and I would like the horizontal lines between rows to show when published: they show up on PDF export, but not on HTML export. Do you know why?

Answer 1

One option is to add CSS within your org file, which will also avoid having to insert a hline between each row in the table. Table attributes can be customized further, but to get horizontal borders for all rows the following could be used:

#+HTML_HEAD: <style type="text/css">
#+HTML_HEAD: tr {border-bottom: 1px solid;}
#+HTML_HEAD: </style>
|   A |   B |   C |
|-----+-----+-----|
| 123 | 123 | 123 |
|   4 |   5 |   5 |
|   3 |   2 |   1 |
|     |     |     |

As mentioned it the org manual, this will override any settings from org-html-table-default-attributes.

---

To add borders for only certain rows, the CSS can be modified to use nth-child. For example, to add a border to only the first 3 rows:

#+HTML_HEAD: <style type="text/css">
#+HTML_HEAD: tr:nth-child(-n+3) {border-bottom: 3px solid;}
#+HTML_HEAD: </style>