How to align content of a div to the bottom

Question

Say I have the following CSS and HTML code:

The header section is fixed height, but the header content may change.

I would like the content of the header to be vertically aligned to the bottom of the header section, so the last line of text "sticks" to the bottom of the header section.

So if there is only one line of text, it would be like:

-----------------------------
| Header title
|
|
|
| header content (resulting in one line)
-----------------------------

And if there were three lines:

-----------------------------
| Header title
|
| header content (which is so
| much stuff that it perfectly
| spans over three lines)
-----------------------------

How can this be done in CSS?

Answer 1

Relative+absolute positioning is your best bet:

#header {
  position: relative;
  min-height: 150px;
}

#header-content {
  position: absolute;
  bottom: 0;
  left: 0;
}

#header, #header * {
  background: rgba(40, 40, 100, 0.25);
}

<div id="header">
  <h1>Title</h1>
  <div id="header-content">Some content</div>
</div>

But you may run into issues with that. When I tried it I had problems with dropdown menus appearing below the content. It's just not pretty.

Honestly, for vertical centering issues and, well, any vertical alignment issues with the items aren't fixed height, it's easier just to use tables.

Example: Can you do this HTML layout without using tables?