This CSS Border Elements Online Test helps you to Boost your Knowledge in PHP. In the CSS border element, there is one element called border-bottom which always sets the values of all of the properties that it can set, even if they are not specified or the value is not defined. One more element which is border-style that can be used to style in different ways like all four borders same value, two border same value, three have the same value and all four have the different value. There is also a property that is used to specify the placement which is called "clear".