CSS task: three div blocks are stacked vertically, each with margin-top 10px and margin-bottom 30px. What will be the distance between the blocks? What will change if you replace div with span?

If three div blocks are stacked vertically, each with margin-top: 10px and margin-bottom: 30px, the space between the blocks will not be 40px, but 30px. This occurs due to margin collapsing: adjacent vertical margins between blocks do not add up, but the larger of the two is used.

In this case, between the blocks, the margin-bottom is 30px and margin-top is 10px, so the distance will be 30px.

If you replace div with span, the behavior will change because span is an inline element, and margin-top and margin-bottom usually do not affect vertical spacing for inline elements. As a result, margins may not be applied or may behave differently, and the blocks will not be stacked vertically but instead will be in a single line unless the display property is changed.