See this Fiddle, how can I center the blue div without fixed width and height in the parent and child?
This is to post in SO
<div class="parent">
<div class="child">
</div>
</div>
Update
These are positioned elements, I want child at the center of the screen.
Update 2
See it centered here, but I can't use fixed widths nor heights in parent neither children. I need positioned elements because I need them to be over other elements.
To center a div, you simply have to add this attribute:
margin-left: auto;
margin-right: auto;
or a more condensed version (assuming 0px for the top and bottom margin):
margin: 0px auto;
This assumes that you have some sort of width value on that element you want to center, whether fixed or a percentage. You shouldn't need anything in the parent to dictate the child's margins.
margin-top: -50%; /* why this takes the width of the parent ???? */
It's because your parent div has position: fixed and your child div has position: absolute and since absolute position element is positioned relative to the first parent element that has a position other than static.
So your child div will take a margin top and margin left with a value equal to -50% of your parent width which is -50% * 150 = 75px
Try this it's display in center of width.
<div class="parent">
<div class="child">
</div>
</div>
<style type="text/css">
.parent{
}
.child{
background: none repeat scroll 0 0 lightblue;
height: 50px;
margin: 0 auto;
width: 150px;
}
</style>
I think this could solve your problem, but this needs JQuery[.width()].
.parent{
position: fixed;
/* I can't use static width nor height, TO DELETE(try changing this)*/
width: 500px;
height: 400px;
background: red;
}
.child{
display: inline-block;
position: absolute;
/*Simulate width and height, these are actually calculated by content*/
width: 100px;
height:50px;
background: lightblue;
}
JQuery onLoad:[JSFiddle]
$(function changePostion() {
var s = $(".parent").width();
var e = $(".child").width();
var d= (s-e)/2;
$(".child").css({"left":d});
var sh = $(".parent").height();
var eh = $(".child").height();
var dh= (sh-eh)/2;
$(".child").css({"top":dh});
});
This article is a best tutorial for positioning html attribute in center. There might be a better way to do without using JQuery.
Dynamic modals can be the biggest pains in the world. You need JS to change the heights and widths. Can you use a plugin? If so here are some good options. Twitter bootstrap has a modal that's very easy to get set up but it's challenging to load divs via ajax and iframes. You have to choose one or the other. simplemodal (http://www.ericmmartin.com/projects/simplemodal/) is good but you still need to do a lot of the work yourself. It works with iframes and ajax content.
I am trying to set the width of the .full_height_div element using pure css, based on its height. It has to be width-relative-to-height, and not height-relative-to-width. The reason for this is that the parent container (.set_rectangle_height) is already a div with height relative to the page width. Obviously, as the page is resized the divs on the page will resize, so i cannot set a fixed width in px for the .full_height_div child.
So .rectangle and .set_rectangle_height make up the parent container which has a width as a percentage of the page and a height relative to this width. See here for an explanation for this method.
But the problem is that then I want to place a div inside the parent with height: 100% and width relative to this height. The aim is then that I will be able to alter the browser window size and everything will keep its aspect ratio.
here is my failed attempt:
.rectangle
{
position: relative;
width: 30%;/*the outermost div is always a % of the page
width, even while resizing*/
display:inline-block;
background-color: green;
}
.set_rectangle_height
{
padding-bottom: 30%;/*this sets the height of the outermost div
to a ratio of 1:3*/
position: relative;
float: left;
width: 100%;
height: 100%;
}
.full_height_div/*this is the div that i want to have a width relative
to its height*/
{
height: 100%;
width: 20px;/*i will delete this once .square_set_width is working*/
position: absolute;
background-color: red;
}
.square_set_width
{
display: inline-block;
padding-left: 100%; /*i want to use something like this line to set
the width of this div to be equal to .full_height_div's height - ie a 1:1 aspect
ratio, but padding-left does not work :( */
position: relative;
height: 100%;
background-color: blue;
}
<div class='rectangle'>
<div class='set_rectangle_height'>
<div class='full_height_div'>
<div class='square_set_width'></div>
</div>
</div>
</div>
So, this is what the above incorrect markup looks like:
And this is what i want it to look like:
I know I could find the blue square percentage height in javascript, then set the width to be equal to this height, but it would be really handy if there is a pure css fix for what I am trying to do. I will be using this structure a lot and I don't really want to go writing code to resize all the divs on my page.
you have to use javascript for that. If I understood you, you want a perfect blue square. Use
var height = $('.square_set_width').height();
$('.square_set_width').css('width',height);
here is a jsfiddle: http://jsfiddle.net/a8kxu/
Edit: instead of doing padding-bottom: 30% do height: 70% instead. Here is another fiddle: http://jsfiddle.net/a8kxu/1/
Edit #2: Sorry, but you cant use css to do this. Its not powerful enough
If i understand you correctly
you can do
#divID {
width: 75%;
margin-left: auto; // this is used to center the container
margin-right: auto;// this as well
}
I have a middle container that takes up whatever vertical space is left on the screen. In it, I placed a Jquery scroller that is currently set to 200px:
.scroll-pane
{
width: 100%;
height: 200px;
overflow: auto;
}
.horizontal-only
{
height: auto;
max-height: 100%;
}
However, if I set .scroll-pane height to 100%, it just removes the scrollbar and stretches the whole page.
See JsFiddle here
How can I stop this? Thanks!
Here is my solution to this problem (jsfiddle). It uses markup like this:
<div id="top">...</div>
<div id="wrapper">
<div id="middle">...</div>
</div>
<div id="bottom">...</div>
The top and bottom divs are position absolutely at the top and bottom, with a width of 100%. The wrapper div has height: 100%, box-sizing: border-box, and top and bottom padding equal to the height of the top and bottom divs, respectively. This causes it to fill the viewport but have padding underneath the top and bottom divs. The middle div has a height of 100% so it fills the content box of the wrapper (i.e., 100% minus the top and bottom paddings). It has position: relative, which leaves you free to use height: 100% on both interior boxes.
Lastly, middleleft is positioned absolutely and middleright has a left margin equal to its width, which causes it to fill the remaining horizontal space.
height: 100% never works like you want it to. The CSS specifications dictate that it must equal the height of the browser window, or the closest parent block-level element with an absolute height specified. That means that this code will should not work as expected:
<!DOCTYPE html>
<html>
<head>
<title>Want the body to fill the page? Too bad!</title>
<style type="text/css">
html, body {
height: 100%;
}
.page {
padding-top: 50px;
box-sizing: border-box;
height: 100%;
}
.header {
margin-top: -50px;
height: 50px;
}
.body {
height: 100%;
background: gray;
}
</style>
</head>
<body>
<div class="page">
<div class="header">
<h1>Too bad!</h1>
</div>
<div class="body">
<p>Hello cruel world...</p>
</div>
</div>
</body>
</html>
However, that works fine in Chrome. Why? I can only assume that Google decided to specifically go against web standards because in this case, the standards make no sense. Why would I want something to be the exact height of the browser window? The only time is a <div> wrapping the whole page; in this case a simple "height is relative to the parent block" rule works just fine without breaking expectations elsewhere.
There is a way around this, though. At least, that's what I wanted to say before I tried this in Firefox too. Another way to get height: 100% (with some restrictions) is with position: absolute. However, it would seem that Firefox isn't respecting position: relative on a display: table-cell element - probably those pesky standards again. Here's the code for this technique anyway, if you are interested:
#wrapper > div > #middleleft {
position: relative;
}
.scroll-pane {
position: absolute;
top: 0;
right: 0;
bottom: 0;
left: 0;
}
So what can you do? Well, unfortunately, I don't yet know the answer to that. A kludgy solution would be to have Javascript set the height to an absolute pixel value, and attach an event to window resizing in order to update that height. I'll get back to you if I find a better way.
I'm not sure exactly what your trying to do, but another method would be to set body height to 100%, then set scrollpane to "height: auto". Then for the "top" and "bottom" div's used fixed positioning, plus margin equal to top/bottom height.
body {
height: 100%;
}
.top {
position: fixed;
top: 0;
height: 100px;
}
.middle {
height: auto;
margin: 100px auto;
}
.bottom {
position: fixed;
bottom: 0;
height: 100px;
}
<div class="top">content</div>
<div class="middle">content</div>
<div class="bottom">content</div>
Try that...
I need to center images that will be wider than the parent div that contains them. the parent div is a fixed width and has the overflow set to hidden.
<div style='overflow:hidden; width:75px height:100px;'>
<img src='image.jpg' style='height:100px;' />
</div>
I must use an image as the child element because I need to resize the thumbnail dimensions and cannot rely on background-size since it is not supported on older versions of mobile safari which is a requirement. I also cannot use javascript for this, so it must be a css solution.
One more thing to note is that widths will vary between images, so I can't just use absolute positioning on the child element at a hard-coded offset.
Is this possible?
UPDATE:
for posterity, I've just found out that this can be accomplished on the older versions of mobile safari by using
-webkit-background-size:auto 100px;
of course, the background will be set as usual using 50% for left positioning. If you need this to work on another browser, the accepted solution is probably the best, but since this question was related to the iphone, this solution is a little cleaner.
How adverse are you to extra markup? Also, is there a max size for the images? For example, if your max image width is 225px then you could try:
<div class="frame">
<div>
<img src="image.jpg"/>
</div>
</div>
.frame {
overflow: hidden;
width: 75px;
height: 100px;
position: relative;
}
.frame > div {
position: absolute;
left: -5075px;
width: 10225px;
text-align: center;
}
.frame img {
height: 100px;
display: inline-block;
}
A fiddle example here: http://jsfiddle.net/brettwp/bW4xD/
Wouldn't using a background image still work? You shouldn't need to resize it.
Does something like this make sense? http://jsfiddle.net/QHRHP/44/
.container{
margin:0 auto;
width:400px;
border:2px solid #000;
height:250px;
background:url(http://placekitten.com/800/250) center top no-repeat;
}
Well if you know the width of the div and the width of the image, you can simply do some math.
Let's say the div is width 200px and the image is width 300px:
div.whatever {
width: 200px;
}
img.someImg {
left: -50px;
position: relative;
}
We know that since the width of the div is 200 pixes, then 100 pixels will be cropped from the image. If you want to center the image, then 50 pixels be hidden past the boundaries of the div on either side. Thus, we set the left position of the image to -50px.
Example (knowing the image size): http://jsfiddle.net/7YJCD/4/
Does that make sense?
If you don't know the image size or the div size, you can use javascript to detect these values and do the same thing.
Example (not knowing the image size, using jQuery javascript): http://jsfiddle.net/K2Rkg/1/
Just for reference, here's the original image.
How do I get a div to automatically adjust to the size of the background I set for it without setting a specific height (or min-height) for it?
There is a very nice and cool way to make a background image work like an img element so it adjust its height automatically. You need to know the image width and height ratio. Set the height of the container to 0 and set the padding-top as percentage based upon the image ratio.
It will look like the following:
div {
background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
background-size: contain;
background-repeat: no-repeat;
width: 100%;
height: 0;
padding-top: 66.64%; /* (img-height / img-width * container-width) */
/* (853 / 1280 * 100) */
}
You just got a background image with auto height which will work just like an img element. Here is a working prototype (you can resize and check the div height): http://jsfiddle.net/8m9ur5qj/
Another, perhaps inefficient, solution would be to include the image under an img element set to visibility: hidden;. Then make the background-image of the surrounding div the same as the image.
This will set the surrounding div to the size of the image in the img element but display it as a background.
<div style="background-image: url(http://your-image.jpg);">
<img src="http://your-image.jpg" style="visibility: hidden;" />
</div>
There is no way to auto adjust for background image size using CSS.
You can hack around it by measuring the background image on the server and then applying those attributes to the div, as others have mentioned.
You could also hack up some javascript to resize the div based on the image size (once the image has been downloaded) - this is basically the same thing.
If you need your div to auto-fit the image, I might ask why don't you just put an <img> tag inside your div?
This answer is similar to others, but is overall the best for most applications. You need to know the image size before hand which you usually do. This will let you add overlay text, titles etc. with no negative padding or absolute positioning of the image. They key is to set the padding % to match the image aspect ratio as seen in the example below. I used this answer and essentially just added an image background.
.wrapper {
width: 100%;
/* whatever width you want */
display: inline-block;
position: relative;
background-size: contain;
background: url('https://upload.wikimedia.org/wikipedia/en/thumb/6/67/Wiki-llama.jpg/1600px-Wiki-llama.jpg') top center no-repeat;
margin: 0 auto;
}
.wrapper:after {
padding-top: 75%;
/* this llama image is 800x600 so set the padding top % to match 600/800 = .75 */
display: block;
content: '';
}
.main {
position: absolute;
top: 0;
bottom: 0;
right: 0;
left: 0;
color: black;
text-align: center;
margin-top: 5%;
}
<div class="wrapper">
<div class="main">
This is where your overlay content goes, titles, text, buttons, etc.
</div>
</div>
I looked at some of the solutions and they're great but I think I found a surprisingly easy way.
First, we need to get the ratio from the background image. We simply divide one dimension through another. Then we get something like for example 66.4%
When we have image ratio we can simply calculate the height of the div by multiplying the ratio by viewport width:
height: calc(0.664 * 100vw);
To me, it works, sets div height properly and changes it when the window is resized.
Maybe this can help, it's not exactly a background, but you get the idea:
<style>
div {
float: left;
position: relative;
}
div img {
position: relative;
}
div div {
position: absolute;
top:0;
left:0;
}
</style>
<div>
<img src="http://antwrp.gsfc.nasa.gov/apod/image/0903/omegacen_davis.jpg" />
<div>Hi there</div>
</div>
Pretty sure this will never been seen all the way down here. But if your problem was the same as mine, this was my solution:
.imaged-container{
background-image:url('<%= asset_path("landing-page.png") %> ');
background-repeat: no-repeat;
background-size: 100%;
height: 65vw;
}
I wanted to have a div in the center of the image, and this will allow me of that.
There is a pure CSS solution that the other answers have missed.
The "content:" property is mostly used to insert text content into an element, but can also be used to insert image content.
.my-div:before {
content: url("image.png");
}
This will cause the div to resize its height to the actual pixel size of the image. To resize the width too, add:
.my-div {
display: inline-block;
}
The recently introduced CSS aspect-ratio attribute (~2020-2021) is a great way to do this without padding hacks and is supported on all evergreen browsers.
Since we need to know the aspect ratio of the image ahead of time, and in many usecases you'll be able to predetermine the image dimension ratio ahead of time (but not always for user generated content), you can either hardcode a single style or inline the css when necessary.
aspect-ratio will calculate the height when the width is specified, based on the provided ratio (or calculate width, if the height is specified).
div {
aspect-ratio: 3 / 2; /*common ratio, like an 800*600px image */
width: 200px; /* computed height will be 133.33px, which is width/aspect-ratio */
background: red; /* so any image bleed is shown*/
background-image: url('https://images.unsplash.com/photo-1631163190830-8770a0ad4aa9?ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=200&q=80');
}
<div></div>
You can do it server side: by measuring the image and then setting the div size, OR loading the image with JS, read it's attributes and then set the DIV size.
And here is an idea, put the same image inside the div as an IMG tag, but give it visibility: hidden + play with position relative+ give this div the image as background.
I had this issue and found Hasanavi's answer but I got a little bug when displaying the background image on a wide screen - The background image didn't spread to the whole width of the screen.
So here is my solution - based on Hasanavi's code but better... and this should work on both extra-wide and mobile screens.
/*WIDE SCREEN SUPPORT*/
#media screen and (min-width: 769px) {
div {
background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
background-size: cover;
background-repeat: no-repeat;
width: 100%;
height: 0;
padding-top: 66.64%; /* (img-height / img-width * container-width) */
/* (853 / 1280 * 100) */
}
}
/*MOBILE SUPPORT*/
#media screen and (max-width: 768px) {
div {
background-image: url('http://www.pets4homes.co.uk/images/articles/1111/large/feline-influenza-all-about-cat-flu-5239fffd61ddf.jpg');
background-size: contain;
background-repeat: no-repeat;
width: 100%;
height: 0;
padding-top: 66.64%; /* (img-height / img-width * container-width) */
/* (853 / 1280 * 100) */
}
}
As you might have noticed, the background-size: contain; property doas not fit well in extra wide screens, and the background-size: cover; property does not fit well on mobile screens so I used this #media attribute to play around with the screen sizes and fix this issue.
This Worked For Me:
background-image: url("/assets/image_complete_path");
background-position: center; /* Center the image */
background-repeat: no-repeat; /* Do not repeat the image */
background-size: cover;
height: 100%;
If it is a single predetermined background image and you want the div to to be responsive without distorting the aspect ratio of the background image you can first calculate the aspect ratio of the image and then create a div which preserves it's aspect ratio by doing the following:
Say you want an aspect ratio of 4/1 and the width of the div is 32%:
div {
width: 32%;
padding-bottom: 8%;
}
This results from the fact that padding is calculated based on the width of the containing element.
Adding to the original accepted answer just add style width:100%; to the inner image so it will auto-shrink/expand for mobile devices and wont end up taking large top or bottom margins in mobile view.
<div style="background-image: url(http://your-image.jpg);background-position:center;background-repeat:no-repeat;background-size: contain;height: auto;">
<img src="http://your-image.jpg" style="visibility: hidden; width: 100%;" />
</div>
How about this :)
.fixed-centered-covers-entire-page{
margin:auto;
background-image: url('https://i.imgur.com/Ljd0YBi.jpg');
background-repeat: no-repeat;background-size:cover;
background-position: 50%;
background-color: #fff;
left:0;
right:0;
top:0;
bottom:0;
z-index:-1;
position:fixed;
}
<div class="fixed-centered-covers-entire-page"></div>
Demo: http://jsfiddle.net/josephmcasey/KhPaF/
I would do the reverse and place the image inside of the main div with a width of 100%, which will make both the div and image responsive to screen size,
Then add the content within an absolute positioned div with width and height of 100% inside of the main div.
<div class="main" style="position: relative; width: 100%;">
<img src="your_image.png" style="width: 100%;">
<div style="position: absolute; width: 100%; height: 100%; display: flex...">
YOUR CONTENT
</div>
</div>
May be this can help, it's not exactly a background, but you get the simple idea
<style>
div {
float: left;
position: relative;
}
div img {
position: relative;
}
div div {
position: absolute;
top:0;
left:0;
}
</style>
<div>
<img src="http://www.planwallpaper.com/static/images/recycled_texture_background_by_sandeep_m-d6aeau9_PZ9chud.jpg" />
<div>Hello</div>
</div>
You can do something like that
<div style="background-image: url(http://your-image.jpg); position:relative;">
<img src="http://your-image.jpg" style="opacity: 0;" />
<div style="position: absolute;top: 0;width: 100%;height: 100%;">my content goes here</div>
</div>
If you know the ratio of the image at build time, want the height based off of the window height and you're ok targeting modern browsers (IE9+), then you can use viewport units for this:
.width-ratio-of-height {
overflow-x: scroll;
height: 100vh;
width: 500vh; /* width here is 5x height */
background-image: url("http://placehold.it/5000x1000");
background-size: cover;
}
Not quite what the OP was asking, but probably a good fit for a lot of those viewing this question, so wanted to give another option here.
Fiddle: https://jsfiddle.net/6Lkzdnge/
Suppose you have some thing like this:
<div class="content">
... // inner HTML
</div>
and you want add a background to it, but you do not know the dimension of the image.
I had a similar problem, and I solved it by using grid:
HTML
<div class="outer">
<div class="content">
... // inner HTML
</div>
<img class="background" />
</div>
CSS
.outer{
display: grid;
grid-template: auto / auto;
// or you can assign a name for this block
}
.content{
grid-area: 1 / 1 / 2 / 2;
z-index: 2;
}
.background{
grid-area: 1 / 1 / 2 / 2;
z-index: 1;
}
z-index is just for placing image actually at the background, you can of course place img.background above the div.content.
NOTE: it might cause the div.content has same height of the picture, so if div.content have any children that placed according to its height, you might want set a number not something like 'auto'.
inspired by the most liked answer, I ended up coming up with a solution using min-height and 'vw' unit
I had an image in a very unusual proportion
through experimentation I ended up using
min-height: 36vw;
that value must change, according to the ratio of your image
css code used im my actual page:
background:url('your-background-image-adress') center center no-repeat;
background-size: 100%;
background-position: top center;
margin-top: 50px;
width: 100%;
min-height: 36vw;
code pen example https://codepen.io/viniciusrad/pen/GRNPXoL
Had this issue with the Umbraco CMS and in this scenario you can add the image to the div using something like this for the 'style' attribute of the div:
style="background: url('#(image.mediaItem.Image.umbracoFile)') no-repeat scroll 0 0 transparent; height: #(image.mediaItem.Image.umbracoHeight)px"
I have been dealing with this issue for a while and decided to write a jquery plugin to solve this problem.
This plugin will find all the elements with class "show-bg" (or you can pass it your own selector) and calculate their background image dimensions.
all you have to do is include this code, mark the desired elements with class="show
Enjoy!
https://bitbucket.org/tomeralmog/jquery.heightfrombg
The best solution i can think of is by specifying your width and height in percent . This will allow you to rezise your screen based on your monitor size. its more of responsive layout..
For an instance.
you have
<br/>
<div> . //This you set the width percent to %100
<div> //This you set the width percent to any amount . if you put it by 50% , it will be half
</div>
</div>
This is the best option if you would want a responsive layout, i wouldnt recommend float , in certain cases float is okay to use. but in most cases , we avoid using float as it will affect a quite of number of things when you are doing cross-browser testing.
Hope this helps :)
actually it's quite easy when you know how to do it:
<section data-speed='.618' data-type='background' style='background: url(someUrl)
top center no-repeat fixed; width: 100%; height: 40vw;'>
<div style='width: 100%; height: 40vw;'>
</div>
</section>
the trick is just to set the enclosed div just as a normal div with dimensional values same as the background dimensional values (in this example, 100% and 40vw).
I solved this using jQuery. Until new CSS rules allow for this type of behavior natively I find it is the best way to do it.
Setup your divs
Below you have your div that you want the background to appear on ("hero") and then the inner content/text you want to overlay on top of your background image ("inner"). You can (and should) move the inline styles to your hero class. I left them here so it's quick and easy to see what styles are applied to it.
<div class="hero" style="background-image: url('your-image.png'); background-size: 100%; background-repeat: no-repeat; width: 100%;">
<div class="inner">overlay content</div>
</div>
Calculate image aspect ratio
Next calculate your aspect ratio for your image by dividing the height of your image by the width. For example, if your image height is 660 and your width is 1280 your aspect ratio is 0.5156.
Setup a jQuery window resize event to adjust height
Finally, add a jQuery event listener for window resize and then calculate your hero div's height based off of the aspect ratio and update it. This solution typically leaves an extra pixel at the bottom due to imperfect calculations using the aspect ratio so we add a -1 to the resulting size.
$(window).on("resize", function ()
{
var aspect_ratio = .5156; /* or whatever yours is */
var new_hero_height = ($(window).width()*aspect_ratio) - 1;
$(".hero").height(new_hero_height);
}
Ensure it works on page load
You should perform the resize call above when the page loads to have the image sizes calculated at the outset. If you don't, then the hero div won't adjust until you resize the window. I setup a separate function to do the resize adjustments. Here's the full code I use.
function updateHeroDiv()
{
var aspect_ratio = .5156; /* or whatever yours is */
var new_hero_height = ($(window).width()*aspect_ratio) - 1;
$(".hero").height(new_hero_height);
}
$(document).ready(function()
{
// calls the function on page load
updateHeroDiv();
// calls the function on window resize
$(window).on("resize", function ()
{
updateHeroDiv();
}
});
If you can make an image on Photoshop where the main layer has an opacity of 1 or so and is basically transparent, put that img in the div and then make the real picture the background image. THEN set the opacity of the img to 1 and add the size dimensions you want.
That picture is done that way, and you can't even drag the invisible image off the page which is cool.
just add to div
style="overflow:hidden;"