Interactive Card

Things to notice about the code: making the shadow. The first two numbers (in pixels)
are the vertical, horizontal range of the shadow, the third is that of the blur.

We are changing width, background color and text-size. The transition command
requires over how long this will happen, in seconds; the on hover specification
tells us the new values for these.

The changes are on the div itself; the user only needs to be told to hover for the
transition to happen!!

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Same card, different elements: changing color and substituting text for image.
the transition here is on the opacity setting: from 0.15 to 1.0, on 4 seconds...