I have another possibility. This is of course a “newer” technique, but for my projects works sufficient.
It only works if you need one or two borders. I’ve never done it with 4 borders… and to be honest, I don’t know the answer for that yet.
.your-item {
position: relative;
}
.your-item:after {
content: '';
height: 100%; //You can change this if you want smaller/bigger borders
width: 1px;
position: absolute;
right: 0;
top: 0; // If you want to set a smaller height and center it, change this value
background-color: #000000; // The color of your border
}