By adjusting the Item Border Radius of the item you control the corners of your cards. This helps when you want to nice rounded corners. The same option exists for an active card.

You can personalize your WordPress timeline even further with the option to manually adjust the radius of your corners.

Make your cards more rounded with this option
If the value is set to 0 the corners will be sharp

Setting the value to “0” will make the item squared. Input the value that you want and watch as it gets applied to all your cards at once.