So you can tweak the positional difference between the placeholder text and value simply by tweaking the padding or line-height using that pseudo-element selector: input[type=text] { padding:4px; } input[type=text]::-webkit-input-placeholder { padding-top:5px; } Or whatever.
Identifying and describing action-reaction force pairs is a simple matter of identifying the two interacting objects and making two statements describing who is pushing on whom and in what direction. For example, consider the interaction between a baseball bat and a baseball.
A force in mechanics is a concept that has both a size and a direction. The net force acting on an object is the sum of the forces onto the object, taking into account both their sizes, and their directions. For example, if an object has two forces acting on it, with equal sizes but in opposite directions, then the net force will be zero (technically: a null vector). If instead the forces are of equal size and in the same direction, then the net force is equal to twice either force.