Why Does `vertical-align` Affect More Than Just the Targeted Element?

Vertical Alignment: Understanding the Unexpected

When exploring the functionality of vertical-align, we encounter a peculiar phenomenon. In theory, applying vertical-align to an inline element, such as a , should align only that element. However, in practice, we observe that other elements, like the containing

, also seem to be vertically aligned.

Expected Behavior or Something Else?

This behavior is indeed the expected outcome. Vertical-align specifies the alignment of elements within a line box. When applied to a particular element, it does not solely adjust the position of that element's content but rather influences the overall alignment of the entire line.

Vertical Alignment Mechanism

Without specifying vertical-align, elements are aligned by their baselines. When vertical-align is introduced, it establishes a new reference line within the line box. Non-aligned elements will align to this reference line, while aligned elements will be positioned either above or below it.

In the example provided:

• The

  and have no inherent alignment.

• When vertical-align is applied to the , it establishes a new reference line in the middle of its height.
• The

  aligns to this reference line, elevating its text to appear alongside the .

• The 's text remains aligned to its own baseline, which is lower than the reference line. As a result, the text appears below the text in the

  .

Conclusion

The unexpected alignment observed in this scenario is not a bug but rather the intended effect of vertical-align. By establishing a reference line within the line box, vertical-align ensures that all elements within that line are vertically aligned to each other, including elements that are not explicitly specified.

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