How do I use the z-index properly? - html

See this page here:
http://www.blakearchive.org/blake/public/exhibits/canterburySpecial.html
The menu bar is supposed to go above the text and the red and black gallery menu on the right should go over the menu bar and text.
I've set the z-index for the right column (in which the text sits) and the menu bar to 1, and the z-index of the red and black gallery menu to -1. But the divs still still next to each other, rather than on top of each other as they're supposed to.
The relative css is here:
#menu {
width: 100%;
float: left;
border-top: 5px solid #823
z-index: 1;
}
#columns .right {
float: right;
width: 28%;
height: 90%;
overflow-y: auto;
padding-right: 3%;
padding-left: 1%;
padding-top: 1%;
text-align: justify;
z-index: 1;
}
#menubar {
float: right;
width: 18%;
padding-right: 3%;
padding-left: 1%;
z-index: -1;
}

z-index applies to positioned elements.
Positioned elements are defined as elements for which the position property has a value other than static.
static is the default value.
You haven't applied a different position value to any of your elements.
You probably want position: relative;.

The z-index property will only work when there is also a position property applied (not counting position: static;, which is the default).
All of the following will work, according to the spec:
position: fixed;
position: absolute;
position: relative;
position: sticky; /* Limited support, currently in Firefox and Opera */
The only exceptions are within a flex container or a CSS grid.

Related

absolute div inside absolute div cuts off with respect to relative position

I have 3 divs on top of each other having following css.
.d1 {
position: relative;
background-color: yellow;
height: 50px;
width: 100px;
overflow: hidden;
}
.d2 {
position: absolute;
background-color: green;
height: 25px;
width: 50px;
}
.d3 {
position: absolute;
left: 83px;
}
and the divs that have classes are as follows:
<div class="d1">
<div class="d2">
<div class="d3">text</div>
</div>
</div>
and as a result I see content of d3 cut off because of overflow:hidden in d1.
How can I avoid cut off content of d3 without modifying d1?
Getting around the overflow..
An element can overflow from a relative or absolute positioned parent by setting its position to fixed. An element that has position: fixed will have the default left,right,top, and bottom styles set as auto. This will position .d3 to the top-left of .d2, and then the left: 83px style will push it to the left from there.
Making up the additional space..
However, to get that additional movement to the right as the original markup, you will need to add margin-left: 8px, which will make-up the additional ~8px needed to replicate the original. Further adjustments to the position of .d3 will need to be done by setting the margin style (see below).
Your updated code should look like this..
.d1 {
position: relative;
background-color: yellow;
height: 50px;
width: 100px;
overflow: hidden;
}
.d2 {
position: absolute;
background-color: green;
height: 25px;
width: 50px;
}
.d3 {
position: fixed;
margin-left: 8px;
left: 83px;
}
Some considerations and caveats..
As a previous commenter mentioned, best practice would be to fix your html markup because this solution could cause issues if you ever need to move the position of .d3. For example, setting left,right,top, or bottom will cause the default setting of this style, auto, from being unset, and the element will be positioned relative to the viewport rather than the parent relative or absolute element.

Why doesn't z-index work although with specified "position"?

I have read that in order for z-index to take effect, the CSS elements involved need to have "position" attributes. So I have a menu that I would like to appear over an IMG when someone clicks on the menu icon. I have these styles for the menu and the image in the content area ...
.menu-btn div {
position: absolute;
left: 100%;
top: 0%;
padding-right: 8px;
margin-top: -0.50em;
line-height: 1.2;
font-weight: 200;
vertical-align: middle;
z-index: 99;
}
#personImgDiv {
position: relative;
z-index: 100;
display: table-cell;
width: 80%;
}
However, when I click on the menu icon, the menu is still appearing behind the image -- https://jsfiddle.net/bdcmka1r/2/ . What else am I missing? How do I get the menu to always appear in front?
This is because you're using the wrong selector. .menu-btn is the button class, and it will only affect this button, also there is no way a button can be treated as a container element such as div, nav, header ..etc. Your correct selector will be nav since your menu contained within nav tags. So, you need to add the position and z-index properties to nav selector instead.
nav {
display: none;
width: 100vw;
padding: 0rem;
background-color: red;
position: absolute;
z-index: 9999;
right: 0%;
top: 100%;
text-align: left;
}
#personImgDiv{
position: relative;
z-index: 100;
}
header{
z-index: 101;
}
I see. you have used z-index:100 in porosinIngDiv and you want to display menu over on image so you have to use z-index more in header then #personImgDiv i have given answer on top it will more clear

z-index - Absolute element inbetween two others

I have a problem understanding z-index properly.
Please have a look at this fiddle I created for you: http://jsfiddle.net/df3EL/
<div id="content">
1. Content
<div id="popup">
3. PopUp
</div>
</div>
<div id="footer">
2. Footer
</div>
I'm aware of positioning and opacity influencing z-index. But with this markup, no matter what I try, the footer is above 1 & 3 or below - never in between.
Is there any way to make the order (1, 2, 3) work, without changing the html markup?
z-index inherits from the parent element
So if your 1 element has a z-index of 100, your 3 element cannot exceed that value in the global scope. In the local scope (within the #content element), the z-index will essentially "reset"
So to make your thing work, you'll need to change the HTML markup to make each element independent (so they can have sequential z-index in the global scope)
if you want popup be hover footer, just set index for footer and popup : http://jsfiddle.net/df3EL/1/
div {
font-family: Verdana;
font-size: 11px;
padding: 20px;
}
div#content {
display: block;
height: 150px;
width: 250px;
background: #eee;
position: relative;
}
div#footer {
display: block;
height: 50px;
width: 250px;
background: #eeefc0;
position: relative;
left: 25px;
top: -25px;
z-index: 1;
}
div#popup {
display: block;
height: 140px;
width: 100px;
background: #C0C0EF;
position: relative;
left: 220px;
top: -5px;
z-index: 2;
}
[http://jsfiddle.net/df3EL/3/][1]
Remove all z-index property except div#popup
It should work in modern browser (suppose ie9+, chrome, opera, FF)
But more logical way move #popup after #footer (may be it should do with javascript when needed to show popup)
You have used position:relative for div#footer and div#popup. Change this to position: absolute and change the vaules top, bottom, left,right to get the desired result.By this you won't have to change your html structure.

Container not resizing for child div

Click here for visual
As you can see from the picture, my parent container is not expanding to fit my child container. The page container (#contain) actually stops at the bottom left hand corner of the kitchen photograph. The child container (#zone2) is clearly overflowing outside its parent container (#contain). I would like to be able to have (#contain) expand automatically to fit (#zone2). The CSS is:
#contain {
position: relative;
width: 100%;
margin: 0 px;
background: #E3DCCC;
z-index: 0;
}
#zone1 {
width: 100%;
height: 850px;
background: url(http://waly1039.com/sites/default/files/k4.jpg) no-repeat center top;
position: absolute;
z-index: -1;
}
#head {
position: absolute;
top: 20px;
width: 100%;
height: 330px;
}
#head img {
max-width: auto;
height: auto;
}
#zone2 {
position: relative;
overflow: hidden;
padding: 3px;
top: 360px;
float: right;
right: 15px;
width: 53%;
height: auto;
border: 4px solid #715E40;
background-color: white;
}
#zone2 img {
max-width:100%;
height: auto;
float:left;
margin: 5px;
}
#zone3 {
position: relative;
top: 710px;
left: 15px;
float: left;
height: 340px;
width: 38%;
border: 4px solid #715E40;
background-color: white;
}
This is a float issue. Try adding the traditional CSS clear fix to #zone2's container:
.container:after{
visibility: hidden;
display: block;
font-size: 0;
content: " ";
clear: both;
height: 0;
}
Be sure to put this in the :after pseudo selector, otherwise it won't work for you. Floated elements exist outside of normal document flow, which is why the container isn't expanding to contain them. The clear fix forces the floats to be cleared, which will cause the container to expand around the bottom of this element.
I tested adding more images to #zone2 and #contain expands vertically. Somehow you've got an element(s) in #zone2 with padding or margins that aren't being added to the parent's total height.
If you want a quick fix in order to move on then add margin-bottom: 30px; to #zone2.
I've duplicated your problem and was able to resolve it with this: You might want to try it. It's looks a bit odd so make a class for it if you like. I'm more concern with where it is placed.
Just beneath lines of your code, add my third line. Just that and you are done. Note, it more about positioning.
<div id="zone3"></div>
<div id="zoneclear"></div>
<br style="clear:both; float:none; display:block; height:1px;" />
Just add the third line.
and just modify one of your styles:
#zoneclear {
clear: both;
float:none;
display:block;
height: 30px;
position: relative;
}
[EDIT]
The codes have a serious bug in firefox which is not present in Google Chrome (that I tested in earlier due to your relative positioning. So I've modified the #zoneclear style to fix that. You might have to test if the other browsers like this hack.
I hope it helps you

Overlapping CSS elements

I would like to make the blue element sit halfway up the green circle and behind it. How can I do that? Also, why is there a random marginal-space between the green circle and the blue element?
#profile-circle {
margin-right: auto; margin-left: auto;
height: 164px; width: 164px;
border-radius: 84px 84px 84px 84px;
}
#main-container {
margin-right: auto; margin-left: auto;
height: 400px; width: 450px;
}
http://jsfiddle.net/LqJ79/
position: relative will help you here. It allows you to use z-index to put the circle over the box, and also you can use top which will move the box relative to its current position. The problem with position: absolute is that it takes the element out of the flow, which is not what you need here I think.
#profile-circle {
position: relative;
z-index: 100;
}
#main-container {
position: relative;
z-index: 50;
top: -100px;
}
See the demo
Use attributes "position: absolute;" in the second box, I updated js fiddle CSS with the following:
#main-container {
margin-right: auto;
margin-left: auto;
height: 400px;
width: 450px;
background-color: blue;
position: absolute;
top: 80px;
}
The easiest way to move the blue element up is to set a negative top margin:
margin-top: -82px;
However, with your current markup, the blue element will sit on top.
You can either put the green element below the blue one in your HTML, then use CSS to slide it up, or you can:
use position: relative; on both elements
set a z-index on the blue and green elements to determine which appears on top (give the green element a higher number so it appears on top)
set top: -82px; on the blue element to slide it up under the green one
The space between them is due to your margins:
margin-top: 15px;
margin-bottom: 5px;
you can make the position: fixed;
top:10px;
left: 10px;
z-index: 1;
and what not in the css to move them around. like this:
http://jsfiddle.net/LqJ79/
The 'magical' space between the two is due to the margin in the div user-info. I changed the CSS to the following:
#user-info {
height: auto;
width: 380px;
margin-right: auto;
margin-left: auto;
}
This will removed the space.