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The position property in CSS sets how an element is positioned in a document. All HTML elements have a position value of static by default, which means positioning is determined by the normal flow of content in the HTML document. In other words, if you have a heading with a paragraph beneath it, and a bulleted list below that paragraph, that’s exactly the order the content will appear in the browser. But what other options do we have for positioning content?
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By default, the position of elements
on the page is determined by
0:00
the normal flow of content
in the HTML document.
0:05
In other words, if you have a heading
with a paragraph beneath it,
0:10
and a bulleted list below that paragraph,
0:14
that's exactly the order that
content will appear in the browser.
0:16
CSS provides various options for
positioning content.
0:22
In this video,
I'll teach you how to position elements in
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the document using the position property.
0:31
I'm looking at the MDN
documentation on CSS positioning.
0:35
The default value is static, which means
the element is positioned according to
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the normal flow of the document.
0:46
In addition, we're able to work
with values called relative,
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absolute, fixed, and sticky.
0:55
Relative positioning is pretty
similar to static positioning.
1:00
As an element set to relative positioning
will still be positioned according
1:05
to the document flow.
1:10
If we set our h1 element
to position: relative,
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We don't see any changes
in our browser preview.
1:29
However, relative positioning
also allows us to offset
1:33
the position of an element
relative to itself.
1:38
We can use properties called top,
right, bottom,
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and left to adjust the positioning
of a relatively positioned element.
1:47
Here, we've moved our h1 element 60
pixels over from the normal left edge.
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Notice that unless we make some sort of
adjustment to the width of this element,
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it's causing horizontal scrolling.
2:09
It's still 100% of the width of
the parent, but moved over 60 pixels.
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You might be thinking,
2:22
"Hmmm. I don't know how often
I'd use positioning to do that.
2:23
It seems better to work with margin and
padding, right?"
2:27
And I agree, so let's see if we can't come
up with a more useful demonstration of
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relative positioning.
2:36
But to do that, let's first take
a look at absolute positioning.
2:38
Absolute positioning removes an element
from the normal document flow.
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And by default,
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allows you to position the element
based on the edges of the viewport.
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Previewing this in the browser,
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we can see that the h1 element has indeed
been removed from the document flow.
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The area above Diane's introductory
paragraph no longer has a heading,
3:15
does it?
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Instead, the heading is now 20 pixels
from the top of the viewport, and
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10 pixels from the right
edge of the viewport.
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The element no longer defaults to
being as wide as the rest of our HTML
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content because it's no longer
part of the same document flow.
3:36
If we add width: 100% to our CSS rule,
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The h1 is now the same
width as the viewport.
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Okay, so that by itself might
not be super useful either.
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And I'm going to delete the rule
I've created for the h1 element.
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But now that we've covered both
relative and absolute positioning,
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we can combine them to create
something interesting.
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When I introduced absolute positioning,
I mentioned that by default,
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elements will be positioned based
on the edges of the viewport.
4:18
However, looking back at the MDN docs,
absolute positioning is
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actually defined as positioned relative
to the closest positioned ancestor.
4:28
In other words, if a parent element
uses relative positioning, we
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can use absolute positioning to position
a child element relative to the parent.
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For example, let's create a caption for
Diane's bio image.
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We'll use the figure and
figcaption elements in our HTML to do so.
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And I'll just reuse my alt
description to create the figcaption.
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By default, the figure element has 40
pixels of margin on the left and right.
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We can eliminate that, but what I'm really
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interested in doing is using relative and
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absolute positioning to place the caption
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on top of developer Diane's image.
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When we set the figure's
position property to relative,
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nothing happens immediately.
6:04
But since figure is the parent
of the figcaption element,
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we can now use absolute positioning
to place the caption over the image.
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Pretty cool, right?
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The caption is 20 pixels from
the bottom edge of the image.
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The only issue is that the caption
is wider than the image.
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I'll give you a moment to see
if you can use your element
6:52
inspector to figure out why.
6:55
Did you get it?
7:01
That was a tough question.
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The issue is, the image element
has a max width of 480 pixels.
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But the figure element is allowed to
extend all the way across the viewport.
7:13
The figcaption element is
the same width as its parent,
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which is the figure element.
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There are a variety of
ways we could fix this.
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One way would be to add figure to the CSS
rule containing the max-width declaration.
7:30
Which would prevent both the figure and
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the image from going
wider than 480 pixels.
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But if you found another solution,
that's great.
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CSS layout challenges rarely
offer only one solution.
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So far, in addition to
the default static positioning,
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we've covered absolute and
relative positioning.
8:03
We'll take a look at our remaining
positioning values, fixed and sticky,
8:07
in our next video.
8:12
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