Div on top of Div using z-index - html

I have the following divs in my HTML:
<div class="main">
<div class="bgimage"></div>
<div class="content">Text</div>
which is directly inside my body.
With the following CSS:
body {
margin: 0;
padding: 20px 0;
}
.content {
filter: alpha(opacity=50);
-moz-opacity: 0.5;
opacity: 0.5;
}
.content {
position: relative;
z-index: 1;
border: #000 thin solid;
width: 960px;
margin-left: auto;
margin-right: auto;
background-color: #000;
}
.bgimage {
position: absolute;
z-index: -1;
width: 1024px;
height: 768px;
margin-left: auto;
margin-right: auto;
background-image: url(bg1.jpg);
}
Basically, I have a Div that with a display of a background image, and I will have another Div on top of this with transparency. This current code works, but my problem is when I am trying to take the content div down from the top.
When I add margin-top:100px, for example, is also brings the image down. I thought it would not touch it if it is not on the same z-index? Why does adding a margin also force the bgimage div down?
I have also tried making the div with class of content a position of absolute and a zindex, but then this won't centre. How should I solve this?

your CSS should be
.bgimage { position: relative; }
.content { position: absolute; }
so the .content will be positioned relative to the .bgimage
your current CSS makes the .bgimage position relative to the document.
see this link on CSS positioning

z-index has no relation to positioning: it only affects the rendering order of your elements. Position: relative tells the browser to render the element at the place it should be, and offset it by eventual left, right, top or bottom coordinates. Therefore, margins, paddings, etc. still affect it.
Only position: absolute guarantees position independance.

I see no need for "z-index"es or "position: absolute" in your code at all -- unless you have other complications that you have not revealed to us.
To center the background on the DIV class="main":
body{margin:0;padding:20px 0;}
.main{background:transparent url(bg1.jpg) no-repeat center top;}
.content{border:#000 thin solid;width:960px;margin-left:auto;margin-right:auto;background-color:#000;opacity: 0.5;filter:alpha(opacity=50);-moz-opacity: 0.5;}
The "center top" places the center-top of the background image on the center-top of the element it's applied to. You may want to apply a
min-width:1024px;_width:1024px;
to the same element -- to prevent a narrower window from hiding the edges (this will change how the element is rendered if the "viewport" is narrower than the background's dimensions).
The only thing your pre-modified code it can do that my modified code can't:
Crop the background image (if it is not natively 1024px x 768px) by using the css "width" and "height" properties
If the class="main" element already has a background image set, most browsers don't support the CSS3 required to stack multiple backgrounds on the same element
Some of what was stated about "z-indexing" and the "position" property above was correct but failed to mention:
you've taken your class="content" element out of "the flow". The ancestor elements won't grow when the content of class="content" element grows. This is an important and fundamental difference between "z-index"ed elements and elements that remain "in the flow".
Other side notes:
elements with the same z-index are stacked according to their order in the HTML (later in the HTML means they are drawn above on the screen)
"z-index"ing requires "position: (absolute|relative)", "z-index: (valid value)", and IIRC "(top|left|bottom|right): (valid value)" to take the element "out of the flow"

CSS absolute positioning is always done "relative" to the most recent ancestor that has a "position: relative", otherwise it uses the body tag by default. If the CSS you included is all that affects those divs, then your .content div will be positioned relative to the .main div, but your .bgImage will be positioned based on the tag.
If you want both .content and .bgImage to move in lockstep, then you'll need to add a "position: relative" to div.main.

Related

CSS, DIV with position: absolute overlaps <p> text

So I've been told (maybe this is wrong) that if you want to overide (go beyond) the margins of a parent div simply make the child position:absolute. The problem with this is that it will overlap text that is set below that div.
Is there a way to;
Override the margins of the parent div and have that div still push down the adjacent text?
Can this be executed by not applying a margin-top: to the first block of text? This solution seems sloppy, the layout would blow up while in mobile view.
Thanks for you help / opinion on this one.
The page in question can be found here.
remove the image background for the div has the position absolute and put the image as a background for the parent div with the following selector:
.entry-content {
padding: 0 40px 40px;
background: url('http://www.gridviper.com/phelan/wp-content/uploads/back-blue-top4.jpg') no-repeat;
background-size: 100% 219px;
}
and change the absolute div css to be as the following:
.content-masthead {
max-width: 100%;
min-height: 219px;
position: relative;
left: 0;
right: 0;
margin-left: 0px;
padding-left: 0px;
}
Few hinds to help you fixing this:
This this not the parent, but the first positioned ancestor (with position other than null, can be "relative").
You can define the size of this element in percentage relative to this ancestor.
You can use padding instead of margin to keep the space.

What's goin' on with img's overflow?

When I hover the icon img's overflow changes. All the code you can find here:
https://jsfiddle.net/DTcHh/12122/
just hover the icon
P.S. I couldn't use z-index:-1, because part of my img goes under
header's background... here is screen:
https://monosnap.com/file/vfivmX7MGJl8bobULiipeToilyTZIx
styles for header:
.header {
background: url("../img/background.png") 100% 100%;
background-size: cover;
max-width: 1920px;
max-height: 900px;
color: white;}
Just remove position: relative; from the CSS of img
.avatar img {
vertical-align: bottom;
position: relative; //remove this style
}
Remove the position: relative;.
.avatar img
{
vertical-align: bottom;
}
If you set position: relative; on an element but no other positioning attributes (top, left, bottom or right), it will no effect on it's positioning at all, it will be exactly as it would be.
There are two things that happen when you set position: relative;. One is that it introduces the ability to use z-index on that element, which doesn't really work with statically positioned elements. Even if you don't set a z-index value, this element will now appear on top of any other statically positioned element. You can't fight it by setting a higher z-index value on a statically positioned element. The 2nd thing that happens is it limits the scope of absolutely positioned child elements. Any element that is a child of the relatively positioned element can be absolutely positioned within that block.

HTML body margin 0 messing up div positioning

I am a bite confused on what is happening here. I put my body margin set to 0 in my css and then all the div elements stretch across the screen like I want, but I want this to apply for only one. From a previous question: HTML Image going across entire screen
An answer said to use position:absolute and then change the position of the div elements. I used to have position:relative on these div elements and when I changed that to absolute, it combined all the div elements in one position. I tried moving them with bottom:then whatever pixels, but still did not move it at all. Would this be the way to move it? What would I do? On W3 schools: http://www.w3schools.com/css/css_positioning.asp
It tells me a lot about positioning div elements, but when I tried to use this it did not work on one div element I tried, but instead overlapped it.
How would I move these div elements?
Code CSS
#middle-4{
position:absolute;
left:0;
right:8;
bottom:0;
top:-800px;}
Code HTML
<div id="middle-4" style="background-image: url(images/Home/rock.png); height: 540px; width: 1348px; border: 1px solid black;"></div>
This is done so for as you can see up to 4 div elements.
If I understand your question correctly you want all element to conform to the default body margin except one element (or multiple elements using a class).
I would do it like this...
Give body a specific margin to ensure it is consistent across browsers.
Use negative horizontal margins to pull your element outside of the constraints of body
body {
margin: 8px;
background: lightGreen;
}
div {
background: lightBlue;
padding: 30px;
border-bottom: 1px solid blue;
}
.fullwidth {
margin-left: -8px;
margin-right: -8px;
}
<div>I'm constrained by body</div>
<div class="fullwidth">I'm full width</div>
<div>I'm constrained by body</div>
Setting margin on body only ensures cross-browser consistency as mentioned by uʍopǝpısdn
If you have 4 divs containing an image each, you should stick to position: relative - this will line up the divs / images vertically on top of each other.
Your issue might have to do with image sizes - if you want all images to keep their original size, you can keep their attributes for width and height as specified in your example "middle-4": height: 540px; width: 1348px;
However - do you want one div / image to stretch across the width of body / screen, you will have to apply the size in percentage - this can be done in 2 ways:
CSS3 - you have the options of "cover" or "contain", which can be applied to div as youre doing it now - example:
div {
background: url(images/Home/rock.png);
background-repeat: no-repeat;
background-position: center;
background-size: cover;
}
CSS2 - you can apply a class to the image itself, and forget about the surrounding div - example:
<img src="images/Home/rock.png" class="img_width" />
.img_width {
width: 100%;
height: auto;
}

div with inline-block not resizing

I have two elements, both with display: inline-block, and the parent has white-space: nowrap.
When the screen is resized, the div on the right side don't resize, like this.
I'm trying to make only the blue div resize.
Full source (jsfiddle)
The structure of the html is like this:
<div class="container">
<div class="header">...</div> <!-- red -->
<div class="aside">...</div> <!-- pink -->
<article>...</article> <!-- blue -->
</div>
Relevant css:
* {
box-sizing: border-box;
}
div.container {
margin: 0 auto;
max-width: 40em;
padding: 0;
white-space: nowrap;
}
div.container > * {
white-space: normal;
}
.aside {
display: inline-block;
max-width: 15em;
vertical-align: top;
}
.article {
display: inline-block;
max-width: 25em;
}
Old question, but for the sake of knowledge of anyone who reads this and also has the doubt:
What I've found is that setting position: relative on the .container
and position: absolute on the .article does what I want.
An absolute positioned element is positioned relative to the nearest positioned ancestor, where a positioned element means anything with a position property different to static, the default; if does not found any positioned element, uses the body element.
The absolute positioned elements, if has their width and heigth in auto, resizes to fit its content, and limits the maximun sizes by its positioned ancestor. You can check this putting a short string instead a large one: the element will shrink to the length of text. If you remove the positioning from div.container, the article (if still positioned absolute) will grow (depending on its content) to cover the space between previous element and body width.
And, related to the aforementioned and to add some utility to this delayed answer, a not-very-know bonus: if you define the right and left properties of a absoluted positioned element, and leave the width in auto, the element will cover the horizontal size between the right and left defined. This way you could put something like
article {
background-color: #a0f4ec;
display: inline-block;
position: absolute;
right: 0;
left: 30%;
}
div.aside {
background-color: #faf;
display: inline-block;
max-width: 15em;
width: 30%;
}
This trick also applies in a vertical sense, but with height, top and bottom properties.
There are a few ways to do it.
Method 1:
two divs the same line, one dynamic width, one fixed
Method 2 (negative margins)
http://alistapart.com/article/negativemargins
Unfortunately, Narxx's answers require the divs to be floated. I'm sure that's what you should do if you're building a real site, but in my case, I'm trying not to use it.
What I've found is that setting position: relative on the .container and position: absolute on the .article does what I want.
Simplified fiddle
If anyone can explain why, I'll mark it as an answer.

Transformed body fixed-position div aligning to body, not window

I have created a <div> fixed, set the following styles on it:
#mydiv {
position: fixed;
left: -150px;
width: 150px;
top: 0;
bottom: 0;
border: 1px solid #f00;
}
This produces a <div> that is offscreen, and presumably the same height as the window.
Then I apply the following styles to the <body>:
body {
-webkit-transform: translate(150px, 0);
}
To my knowledge, this should move the body 150px to the right, thereby moving #mydiv into view. This works, but now #mydiv is the height of the body, not the height of the window.
Here's a JSFiddle example
Is this a Webkit bug? Or is this something I'm doing wrong?
EDIT:
This appears to happen on Firefox as well.
The solution to this problem, while perhaps not immediately intuitive, is pretty straightforward.
html, body {
height: 100%;
}
Normally position: fixed elements are aligned relative to the window (the parent of the html element). When css transforms are applied, however, position: fixed elements are aligned relative to the closest parent with a css transform applied.
The alternate approach Webkit and other browsers could have taken, would be to still align position: fixed elements to the window. But the problem with this would be the position: fixed div would not move at all when the body was transformed, and so the div would still be positioned offscreen.