css effect question

In case of light and shade or color change, it can be just css.

You need to use css3 or JavaScript to make the box shake or stand out

JavaScript has a wide range of browser support, and css3 is clean.

If you want to make it into JavaScript, I recommend a library called jQuery

It's a great library that's been used for a long time and is still widely used

Go around the links below. In css3, when you hover, you can give not only color and shadow, but also simple size and animation.

PS: For your information, the difference between css and css3 that you asked in the comments above is that the range of expressions without using images has diversified. Gradient, border-radius, shadow, etc. can be expressed by themselves without the attached image. (In the past, in order to express a round edge-like crystal, only the corners were made into images and covered on the images.)