What I'm trying to achieve:
Two plus rows with each containing three columns. For the rows, I have specified relative positioning containing three images per row, for two rows. This works fine.
I want layered divs beneath those images, using position absolute and negative z-index, which also works fine for the first row. The second row, the images line up fine, but the absolute positioned divs within appear on the first row.
jsFiddle here:
http://jsfiddle.net/Ajdin/tNGCM/
I've read a few questions on the board, and googled css absolute positioning since that's where I'm thinking I may be misunderstanding something. Please help :)
Since the div ".hireBioImg" set "float" property, it wont be extended the height to its parent. so in hireBioRow, you need to add "clearfix" to wrap float elements inside.
Please see updated here:
http://jsfiddle.net/tNGCM/1/
And more about clearfix:
The problem happens when a floated element is within a container box, that element does not automatically force the container’s height adjust to the floated element. When an element is floated, its parent no longer contains it because the float is removed from the flow.
http://www.webtoolkit.info/css-clearfix.html
Related
I got a DIV in my HTML-Markup, which is positioned relative. The DIVs inside this container are absolute.
this destroys the complete layout, because the following HTML-Elements are now positioned wrong, the (above) DIV which is relative, overflows them...
but why? How can I fix it?
Once you position a container with :relative, everything inside it will be positioned in relation to that. The position:absolute pulls the child elements out of the flow of the page an positions them at the top of the container with position:relative.
Thus, once you have elements with position:relative, you will want to also add rules to move and position the child elements. Consider using left: and top: or right: and bottom to position your :absolute child elements.
Alternatively, you might try to position the child elements with :relative as well, if you don't want them pulled out of the flow of the page.
Do you have code to look at, or a jsfiddle? Otherwise it's difficult to know what's going on and to suggest a fix.
If your relatively-positioned element only contains absolutely-positioned elements, you need to give it a height setting, otherwise it will have zero height (the absolutely-positioned elements won't be counted for auto height), and therefore probably cause some overlapping with subsequent elements.
I'm pretty CSS-savvy, but I'm seeing some odd float/clear behavior. I have it working, but I'm not entirely sure why and am looking for an explanation.
JSFiddle: http://jsfiddle.net/ismyrnow/JV5n6/
I have a 2 column layout - sidebar and content - where the sidebar is floated but the content is not; the content div has a left margin applied to it.
If I use clear:both on any elements in the content div, the element unexpectedly drops below the height of the sidebar div (unexpectedly because the floated sidebar isn't directly affecting the positioning of items inside the content area).
What is even more unexpected, is that when I add overflow:auto to the content div, the problem goes away. (I found the solution here)
Can someone explain:
Why clear:both would cause an element to clear a floated element that isn't directly affecting its position.
Why overflow:auto on the parent element fixes the issue.
Why clear:both would cause an element to clear a floated element that isn't directly affecting its position.
It may not be directly affecting its position, but it would still have affected it anyway, because in the absence of any clearance, floats aren't normally restricted in how they affect the rest of the normal flow layout even once they are taken out of it, not even by different parent elements such as your .b content element with the left margin in this case. The only real restriction is that floating elements may only affect elements that come after them in document tree order, i.e. elements that are following (not preceding) siblings, as well as their descendants.
The content that's just above the element within your content column isn't tall enough to push it beneath the floated element. If you remove that declaration, you would see that both .c elements become positioned next to their respective floats as well.
When you add clear, what happens is that it forces the clearing element to be positioned beneath the float regardless of where it ends up horizontally.
Why overflow:auto on the parent element fixes the issue.
This is because any block boxes with overflow other than visible generate block formatting contexts. A property of a block formatting context is that floating boxes outside it can never interact with any boxes inside it, and vice versa.
Once you cause the content element to establish its own block formatting context, your floating element is no longer able to affect any elements inside the content element (see the section on the float property), and the clearing element inside it is no longer able to clear any floats that are outside the content element (see the clear property).
For clear:both
The clear CSS property specifies whether an element can be next to floating elements that precede it or must be moved down (cleared) below them.
The clear property applies to both floating and non-floating elements.
When applied to non-floating blocks, it moves the border edge of the element down until it is below the margin edge of all relevant floats. This movement (when it happens) causes margin collapsing not to occur.
When applied to floating elements, it moves the margin edge of the element below the margin edge of all relevant floats. This affects the position of later floats, since later floats cannot be positioned higher than earlier ones.
The floats that are relevant to be cleared are the earlier floats within the same block formatting context.
I hope this will clear your doubt.
This is the link from where i found the above info.....
https://developer.mozilla.org/en-US/docs/Web/CSS/clear
First off, please let me say I'm pretty new to CSS. Still lots to learn! I'm working on a site at https://web.archive.org/web/20130709112702/http://www.thesweet-spot.com/test77
Everything is working great, EXCEPT that the main content box is being placed under the fixed-position logo instead of over it, even though the z-index on the logo is lower than the z-index on the content box. What can you geniuses tell me?
There's actually two reasons:
Its parent is set to show up behind the logo. Any z-index applied to elements within that parent element will only apply to other elements within that parent. All the elements within the parent will be stacked accordingly, then that entire element will be put behind the logo as specified by its stack order.
A z-index only applies to elements with position of absolute, fixed, or relative. It does not apply to elements with static position.
It is constrained by the parent container's z-index. You cannot set a child to a higher z-index than the parent; it caps at the parent's value.
You could make the stripes a background of the body tag and then set the container to have no background. Once that is done set container to a higher z-index.`
I ran into a quite annoying problem a few days ago. I'm working on a website with the following structure:
[header]
[menu strip]
[featured stuff]
[contents]
[footer]
(these are all horizontally centered divs under each other with the same fixed width in this order)
Later on I will change the contents of the "contents" part. Inside the "contents" div there will be other divs, sometimes with a fixed height and sometimes not.
Now here's the problem: any time I put another div into the "contents" without a declared height, the inner div renders with 0px. It doesn't matter if the inner div has elements with declared height or not. It works with declared heights, but I cannot guarantee that I will know the height of the contents at all times.
What could be causing this?
This sounds like a clearfix issue when elements inside the div are floating.
The problem happens when a floated
element is within a container box,
that element does not automatically
force the container’s height adjust to
the floated element. When an element
is floated, its parent no longer
contains it because the float is
removed from the flow.
I'm not sure if I fully understand the difference between these two.
Can someone explain why I would use one over the other and how they differ?
You'd use margin, if you wanted to move a (block) element away from other elements in the document flow. That means it'd push the following elements away / further down. Be aware that vertical margins of adjacent block elements collapse.
If you wanted the element to have no effect on the surrounding elements, you'd use positioning (abs., rel.) and the top, bottom, left and right settings.
With relative positioning, the element will still occupy its original space as when positioned statically. That's why nothing happens, if you just switch from static to relative position. From there, you may then shove it across the surrounding elements.
With absolute positioning, you completely remove the element from the (static) document flow, so it will free up the space it occupied. You may then position it freely - but relative to the next best non-statically positioned element wrapped around it. If there is none, it'll be anchored to the whole page.
top is for tweak an element with use of position property.
margin-top is for measuring the external distance to the element, in relation to the previous one.
Also, top behavior can differ depending on the type of position, absolute, relative or fixed.
Margin applies and extends / contracts the element's normal boundary but when you call top you are ignoring the element's regular position and floating it to a specific position.
Example:
html:
<div id="some_element">content</div>
css:
#some_element {margin-top: 50%}
Means the element will begin displaying html at the 50% height of its container (i.e. the div displaying the word "content" would be displayed at 50% height of its containing div or html node directly before div#some_element) but if you open your browser's inspector (f12 on Windows or cmd+alt+i on mac) and mouse over the element you will see it's boundaries highlighted and notice the element has been pushed down rather than re-positioned.
Top on the other hand:
#some_element {top: 50%}
Will actually reposition the element meaning it will still display at 50% of its container but it will reposition the element so its edge starts at 50% of its containing element. In other words, there will be a gap between the edges of the element and its container.
Cheers!
The top property is a position property. It is used with the position property, such as absolute or relative. margin-top is an element's own property.
from bytes:
"Margin is that space between the edge of an element's box and the edge of the complete box, such as the margin of a letter. 'top' displaces the element's margin edge from the containing blocks box, such as that same piece of paper inside a cardboard box, but it is not up against the edge of the container."
My understanding is that margin-top creates a margin on the element, and top sets the top edge of the element below the top edge of the containing element at the offset.
you can try it here:
http://w3schools.com/css/tryit.asp?filename=trycss_position_top
just replace top with margin-top to see the difference.
This is my understanding...
TOP: it defines the position of the element wrt its own elements or other element i.e in case of relative top refers to compare with its own element whereas in fixed top refers to compare with viewport.
Margin_Top: it always refer to its own elements that adds an offset(outside) to its border