Certain borders thicker than others

Hi Tobias,

Some of the borders in my table are thicker than others. Attached is my custom CSS code and an image. Can you let me know what I’m doing wrong?

.tablepress thead th,
.tablepress tfoot th {
	background-color: #000000;
	color: #ffffff;
}

.tablepress .odd td {
	background-color: #ffffff;
	color: #000000;
}

.tablepress .even td {
	background-color: #F2F2F2;
	color: #000000;
}

.tablepress tbody td {
	border: solid 1px;
	border-color: #000000;
}

.tablepress thead th {
	border: 1px solid #000000;
}

Image: https://ibb.co/GFXXRrX

Thanks!

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