How to remove double cell borders in HTML tables

I want a simple 17x2 HTML table with single lines as borders, no spaces between cells etc. This online editor returns the following code:

The output looks like this:

I added cellspacing="0" in order to get rid of the white spaces between cells. How do I get rid of the duplicate border between neighbouring cells?

PS.: The Stackoverflow input editor returns an code indentation error, although all indents are in place.

Solution

You can use the border-collapse: collapse Property on the table tag.

for example:

table {
    border-collapse: collapse;
}