Please check the JSFIDDLE code here.
I have an absolute positioned child and a relative positioned parent. I expect to see the entire absolute positioned child at all circumstances. When I place the overflow : auto for the grandparent, it's hiding the absolute positioned element within the scroll.
What I am seeing is this (Absolute child hidden in scroll):
What I want to see is (Able to see the entire absolute child with overflow: auto set on the grand parent):
.GrandParent {
width: 200px;
height: 200px;
background-color: red;
overflow: auto;
}
.Parent {
width: 150px;
height: 150px;
background-color: blue;
position: relative;
z-index: 500;
}
.Child {
width: 300px;
height: 300px;
background-color: grey;
position: absolute;
left: 0;
top: 100%;
opacity: 0.5;
}
<body>
<div class="GrandParent">
<div class="Parent">
<div class="Child">
</div>
</div>
</div>
</body>
This is because the .Child is relative to the .Parent not the .GrandParent. The .Parent's content is being hidden via overflow: auto on it's container element which is the .GrandParent. One way of solving this issue is to have another container that the .Child is relative to. In my code example below, .Child will no longer be relative to parent so the positioning can get tricky. This is one of the reasons why libraries such as popperjs was created. You will need JavaScript to reposition the .Child on-scroll.
.MainContainer {
position: relative;
}
.GrandParent {
width: 200px;
height: 200px;
background-color: red;
overflow: auto;
}
.Parent {
width: 150px;
height: 150px;
background-color: blue;
z-index: 500;
}
.Child {
width: 300px;
height: 300px;
background-color: grey;
position: absolute;
top: calc(100% - 50px);
left: 0;
opacity: 0.5;
}
.some-modal-content {
height: 1000px;
}
<body>
<div class="MainContainer">
<div class="GrandParent">
<div class="Parent">
<div class="Child">
</div>
</div>
<div class="some-modal-content"></div>
</div>
</div>
</body>
Child is out of the document flow(new block formatting context), just offset relative to Parent；
Child box inside Parent (relative), but overflowed, set Parent overflow property to control layout visibility;
Child + Parent box inside GrandParent, overflowed, set GrandParent overflow property to control layout visibility;
They have a ‘wrapped’ relationship, The content outside the area is controlled by the outer overflow property。
Except for fixed attribute positioning, other positioning is controlled by the wrapping layer, automatically height content, or scrolling, or being cropped and hidden.
position - CSS: Cascading Style Sheets | MDN
overflow - CSS: Cascading Style Sheets | MDN
Through the wrap layer we generally control the display of the inner layer in this way.
active may be come from a click event, or hover event, etc.
<div class="GrandParent active">
<div class="Parent">
<div class="Child"></div>
</div>
</div>
.Child { display:none; ... }
.GrandParent.active .Child { display:block; }
Related
As you can see in the CSS below, I want child2 to position itself before child1. This is because the site I'm currently developing should also work on mobile devices, on which the child2 should be at the bottom, as it contains the navigation which I want below the content on the mobile devices. - Why not 2 masterpages? This is the only 2 divs which are repositioned in the entire HTML, so 2 masterpages for this minor change is an overkill.
HTML:
<div id="parent">
<div class="child1"></div>
<div class="child2"></div>
</div>
CSS:
parent { position: relative; width: 100%; }
child1 { width: auto; margin-left: 160px; }
child2 { width: 145px; position: absolute; top: 0px; bottom: 0px; }
child2 has dynamic height, as different subsites could have more or less navigation items.
I know that absolute positioned elements are removed from the flow, thus ignored by other elements.
I tried setting overflow:hidden; on the parent div, but that didn't help, neither does the clearfix.
My last resort will be JavaScript to reposition the two divs accordingly, but for now I'll try and see if there exist a non-JavaScript way of doing this.
You answered the question yourself:
I know that absolute positioned elements are removed from the flow, thus ignored by other elements.
So you can't set the parents height according to an absolutely positioned element.
You either use fixed heights or you need to involve JavaScript.
Nowadays one might use CSS flexbox or grid layout to reverse the visual order of HTML elements inside a parent container without using position: absolute;. See also Reverse order of columns in CSS Grid Layout
Although stretching to elements with position: absolute is not possible, there are often solutions where you can avoid the absolute positioning while obtaining the same effect. Look at this fiddle that solves the problem in your particular case http://jsfiddle.net/gS9q7/
The trick is to reverse element order by floating both elements, the first to the right, the second to the left, so the second appears first.
.child1 {
width: calc(100% - 160px);
float: right;
}
.child2 {
width: 145px;
float: left;
}
Finally, add a clearfix to the parent and you're done (see the fiddle for the complete solution).
Generally, as long as the element with absolute position is positioned at the top of the parent element, chances are good that you find a workaround by floating the element.
There is a quite simple way to solve this.
You just have to duplicate the content of child1 and child2 in relative divs with display:none in parent div. Say child1_1 and child2_2. Put child2_2 on top and child1_1 at the bottom.
When your jquery (or whatever) calls the absolute div, just set the according relative div (child1_1 or child2_2) with display:block AND visibility:hidden. The relative child will still be invisible but will make parent's div higher.
Feeela is right but you can get a parent div contracting or expanding to a child element if you reverse your div positioning like this:
.parent {
position: absolute;
/* position it in the browser using the `left`, `top` and `margin`
attributes */
}
.child {
position: relative;
height: 100%;
width: 100%;
overflow: hidden;
/* to pad or move it around using `left` and `top` inside the parent */
}
This should work for you.
This question was asked in 2012 before flexbox. The correct way to solve this problem using modern CSS is with a media query and a flex column reversal for mobile devices. No absolute positioning is needed.
https://jsfiddle.net/tnhsaesop/vjftq198/3/
HTML:
<div class="parent">
<div style="background-color:lightgrey;">
<p>
I stay on top on desktop and I'm on bottom on mobile
</p>
</div>
<div style="background-color:grey;">
<p>
I stay on bottom on desktop and I'm on top on mobile
</p>
</div>
</div>
CSS:
.parent {
display: flex;
flex-direction: column;
}
#media (max-width: 768px) {
.parent {
flex-direction: column-reverse;
}
}
With pure JavaScript, you just need to retrieve the height of your static position child element .child1 using the getComputedStyle() method then set that retrieve value as the padding-top for that same child using the HTMLElement.style property.
Check and run the following Code Snippet for a practical example of what I described above:
/* JavaScript */
var child1 = document.querySelector(".child1");
var parent = document.getElementById("parent");
var childHeight = parseInt(window.getComputedStyle(child1).height) + "px";
child1.style.paddingTop = childHeight;
/* CSS */
#parent { position: relative; width: 100%; }
.child1 { width: auto; }
.child2 { width: 145px; position: absolute; top: 0px; bottom: 0px; }
html, body { width: 100%;height: 100%; margin: 0; padding: 0; }
<!-- HTML -->
<div id="parent">
<div class="child1">STATIC</div>
<div class="child2">ABSOLUTE</div>
</div>
There's a very simple hack that fixes this issue
Here's a codesandbox that illustrates the solution: https://codesandbox.io/s/00w06z1n5l
HTML
<div id="parent">
<div class="hack">
<div class="child">
</div>
</div>
</div>
CSS
.parent { position: relative; width: 100%; }
.hack { position: absolute; left:0; right:0; top:0;}
.child { position: absolute; left: 0; right: 0; bottom:0; }
you can play with the positioning of the hack div to affect where the child positions itself.
Here's a snippet:
html {
font-family: sans-serif;
text-align: center;
}
.container {
border: 2px solid gray;
height: 400px;
display: flex;
flex-direction: column;
}
.stuff-the-middle {
background: papayawhip
url("https://camo.githubusercontent.com/6609e7239d46222bbcbd846155351a8ce06eb11f/687474703a2f2f692e696d6775722e636f6d2f4e577a764a6d6d2e706e67");
flex: 1;
}
.parent {
background: palevioletred;
position: relative;
}
.hack {
position: absolute;
left: 0;
top:0;
right: 0;
}
.child {
height: 40px;
background: rgba(0, 0, 0, 0.5);
position: absolute;
bottom: 0;
left: 0;
right: 0;
}
<div class="container">
<div class="stuff-the-middle">
I have stuff annoyingly in th emiddle
</div>
<div class="parent">
<div class="hack">
<div class="child">
I'm inside of my parent but absolutely on top
</div>
</div>
I'm the parent
<br /> You can modify my height
<br /> and my child is always on top
<br /> absolutely on top
<br /> try removing this text
</div>
</div>
I came up with another solution, which I don't love but gets the job done.
Basically duplicate the child elements in such a way that the duplicates are not visible.
<div id="parent">
<div class="width-calc">
<div class="child1"></div>
<div class="child2"></div>
</div>
<div class="child1"></div>
<div class="child2"></div>
</div>
CSS:
.width-calc {
height: 0;
overflow: hidden;
}
If those child elements contain little markup, then the impact will be small.
I had a similar problem.
To solve this (instead of calculate the iframe's height using the body, document or window) I created a div that wraps the whole page content (a div with an id="page" for example) and then I used its height.
"You either use fixed heights or you need to involve JS."
Here is the JS example:
---------- jQuery JS example--------------------
function findEnvelopSizeOfAbsolutelyPositionedChildren(containerSelector){
var maxX = $(containerSelector).width(), maxY = $(containerSelector).height();
$(containerSelector).children().each(function (i){
if (maxX < parseInt($(this).css('left')) + $(this).width()){
maxX = parseInt($(this).css('left')) + $(this).width();
}
if (maxY < parseInt($(this).css('top')) + $(this).height()){
maxY = parseInt($(this).css('top')) + $(this).height();
}
});
return {
'width': maxX,
'height': maxY
}
}
var specBodySize = findEnvelopSizeOfAbsolutelyPositionedSubDivs("#SpecBody");
$("#SpecBody").width(specBodySize.width);
$("#SpecBody").height(specBodySize.height);
There is a better way to do this now. You can use the bottom property.
.my-element {
position: absolute;
bottom: 30px;
}
This is very similar to what #ChrisC suggested. It is not using an absolute positioned element, but a relative one. Maybe could work for you
<div class="container">
<div class="my-child"></div>
</div>
And your css like this:
.container{
background-color: red;
position: relative;
border: 1px solid black;
width: 100%;
}
.my-child{
position: relative;
top: 0;
left: 100%;
height: 100px;
width: 100px;
margin-left: -100px;
background-color: blue;
}
https://jsfiddle.net/royriojas/dndjwa6t/
Also consider next approach:
CSS:
.parent {
height: 100%;
}
.parent:after {
content: '';
display: block;
}
Also since you are trying to reposition divs consider css grid
Absolute views position themselves against the nearest ancestor that isn't statically positioned (position: static), therefore if you want an absolute view positioned against a given parent, set the parent position to relative and the child to position to absolute
Try this, it was worked for me
.child {
width: 100%;
position: absolute;
top: 0px;
bottom: 0px;
z-index: 1;
}
It will set child height to parent height
So basically I have a parent div element containing just one child div element.
Now I want to set the position of child div to absolute (for animation / page-transition effect). But on doing so, height of parent div element gets set to 0 which changes the whole layout which isn't desired.
How do I fix this to set height of parent div element to that of height of absolute positioned child div element
Here's how my that block of code looks
HTML
<div class='parent'>
<div class='child'></div>
</div>
CSS
.parent {
position: relative;
}
.child {
position: absolute;
top: 0;
}
Although stretching to elements with position: absolute is not possible, there are often solutions where you can avoid the absolute positioning while obtaining the same effect. Look at this fiddle that solves the problem in your particular case http://jsfiddle.net/gS9q7/
The trick is to reverse element order by floating both elements, the first to the right, the second to the left, so the second appears first.
.child1 {
width: calc(100% - 160px);
float: right;
}
.child2 {
width: 145px;
float: left;
}
Finally, add a clearfix to the parent and you're done (see the fiddle for the complete solution).
Generally, as long as the element with absolute position is positioned at the top of the parent element, chances are good that you find a workaround by floating the element.
One way you could do this is by setting a variable in CSS and using the variable on both the parent and child elements height and width.
html {
--height: 100px;
--width: 200px;
}
.parent {
position: relative;
border: 1px solid black;
height: var(--height);
width: var(--width);
}
.child {
position: absolute;
height: var(--height);
width: var(--width);
background: red;
top: 0;
}
<div class='parent'>
<div class='child'></div>
</div>
Another would be to use javascript to set the property of the parents width and height to that of the child elements.
const par = document.querySelector('.parent');
const child = document.querySelector('.child');
const getSetStyles = (p, c, arr) => {
const styleArr = {};
arr.map( a => styleArr[a] = getComputedStyle(c).getPropertyValue(a) );
Object.entries(styleArr).map( sArr => par.style.setProperty(sArr[0], `${sArr[1]}`) );
}
getSetStyles(par, child, ['width', 'height'])
html {
--height: 100px;
--width: 200px;
}
.parent {
position: relative;
border: 2px solid black;
}
.child {
position: absolute;
height: var(--height);
width: var(--width);
background: red;
top: 0;
}
<div class="parent">
<div class="child"></div>
</div>
I don't know if I have followed your question correctly, but please set a height for the parent then set the height of child to 100%
.parent {
position: relative;
height: 100px;
width: 100px;
}
.child {
position: absolute;
top: 0;
height: 100%;
width: 100%;
}
I have the following HTML:
<div class="parent">
<div class="child"></div>
</div>
Their CSS are as follows:
.parent {
position: fixed;
}
.child {
position: fixed;
left: calc(100% - 10%);
}
Since both the parent and child are having fixed positions, is there a way that I can make child relative to the parent?
Originally, I wanted to have this:
.parent {
position: relative;
}
.child {
position: absolute;
left: calc(100% - 10%);
}
But, the parent here is a header that remains fixed at the top of every page. Therefore, I can't change it to relative. However, I can do change the child from fixed to absolute if I want to but that is not a concern here. I want the child to be relative to the parent so that the styling has more accuracy for all screen sizes by default. Any workaround for this?
I think you have answered your own question - but here's a snippet to demonstrate that if you position child in relation to its fixed positioned parent it works.
.parent {
position: fixed;
width: 100%;
height: 20vh;
top: 10vh; /* just to prove child is positioned relative to parent not to body */
background-color: lime;
}
.child {
position: absolute;
left: calc(100% - 10%);
width: 50%;
height: 10vh;
background-color: cyan;
}
<div class="parent">
<div class="child"></div>
</div>
I have a div with unknown width and height, this div is one of the children of a bigger div.
#myDiv {
/* Blah blah blah */
}
#inner {
position: absolute;
width: 100%;
height: 100%;
}
<div id="myDiv">
<div id="inner"></div>
</div>
But the problem is that the #inner div doesn't fit properly, it's way bigger than its parent #myDiv while its width and height are set to 100%.
What am I doing wrong?
By making any element position: absolute; means: place me to the first parent that is position: relative; which is not always equal to its parent element.
And if there are other children you need to remember that one of them will be places "under" the element posiotionated absolutely.
Accepted answer didn't solve it for me. Parent element was already position: relative;.
This is what worked for me:
In the child element, instead of using height:100% use top:0; bottom:0; to fill up height, and left:0; right:0; to fill width up.
.child {
top: 0;
bottom: 0;
left: 0;
right: 0;
}
One reason an absolutely-positioned child element can stick out from its relatively-positioned parent is if the parent has padding.
Take the following example:
.parent {
position: relative;
padding: 50px;
width: 250px;
height: 50px;
margin: auto;
background-color: blue;
}
.child {
position: absolute;
width: 100%;
height: 100%;
background-color: #ff000099;
}
<div class="parent">
<div class="child"></div>
</div>
As you can see, the actual width and height of the child is the same as the parent, however since the parent has padding-top and padding-left, the child's content is placed after the parent's padding. This makes the child stick out at the bottom and the right.
There are different ways to handle this, depending on the desired outcome.
If you want the child to perfectly cover the parent, either use bets's solution and set the top, right, bottom and left attributes on the child instead of the width and height, or just keep the width and height at 100% and set top and left to 0, like this:
.parent {
position: relative;
padding: 50px;
width: 250px;
height: 50px;
margin: auto;
background-color: blue;
}
.child {
position: absolute;
width: 100%;
height: 100%;
top: 0;
left: 0;
background-color: #ff000044;
}
<div class="parent">
I am parent content
<div class="child">I am child content</div>
</div>
If you want the child to occupy all the space within the padding on the parent, you can use calc() to remove the parent's padding from the child div:
.parent {
position: relative;
padding: 50px;
width: 250px;
height: 50px;
margin: auto;
background-color: blue;
}
.child {
position: absolute;
width: calc(100% - 100px);
height: calc(100% - 100px);
background-color: #ff000099;
}
<div class="parent">
<div class="child"></div>
</div>
(Just remember to remove both the left and right padding from the child's width and the top and bottom from its height. That's why I am multiplying the padding by 2.)
Combining these, if you want the child to start after the top and left padding, but not stick out the right or bottom, only subtract the top and left paddings from the height and width of the child:
.parent {
position: relative;
padding: 50px;
width: 250px;
height: 50px;
margin: auto;
background-color: blue;
}
.child {
position: absolute;
width: calc(100% - 50px);
height: calc(100% - 50px);
background-color: #ff000099;
}
<div class="parent">
<div class="child"></div>
</div>
As you can see in the CSS below, I want child2 to position itself before child1. This is because the site I'm currently developing should also work on mobile devices, on which the child2 should be at the bottom, as it contains the navigation which I want below the content on the mobile devices. - Why not 2 masterpages? This is the only 2 divs which are repositioned in the entire HTML, so 2 masterpages for this minor change is an overkill.
HTML:
<div id="parent">
<div class="child1"></div>
<div class="child2"></div>
</div>
CSS:
parent { position: relative; width: 100%; }
child1 { width: auto; margin-left: 160px; }
child2 { width: 145px; position: absolute; top: 0px; bottom: 0px; }
child2 has dynamic height, as different subsites could have more or less navigation items.
I know that absolute positioned elements are removed from the flow, thus ignored by other elements.
I tried setting overflow:hidden; on the parent div, but that didn't help, neither does the clearfix.
My last resort will be JavaScript to reposition the two divs accordingly, but for now I'll try and see if there exist a non-JavaScript way of doing this.
You answered the question yourself:
I know that absolute positioned elements are removed from the flow, thus ignored by other elements.
So you can't set the parents height according to an absolutely positioned element.
You either use fixed heights or you need to involve JavaScript.
Nowadays one might use CSS flexbox or grid layout to reverse the visual order of HTML elements inside a parent container without using position: absolute;. See also Reverse order of columns in CSS Grid Layout
Although stretching to elements with position: absolute is not possible, there are often solutions where you can avoid the absolute positioning while obtaining the same effect. Look at this fiddle that solves the problem in your particular case http://jsfiddle.net/gS9q7/
The trick is to reverse element order by floating both elements, the first to the right, the second to the left, so the second appears first.
.child1 {
width: calc(100% - 160px);
float: right;
}
.child2 {
width: 145px;
float: left;
}
Finally, add a clearfix to the parent and you're done (see the fiddle for the complete solution).
Generally, as long as the element with absolute position is positioned at the top of the parent element, chances are good that you find a workaround by floating the element.
There is a quite simple way to solve this.
You just have to duplicate the content of child1 and child2 in relative divs with display:none in parent div. Say child1_1 and child2_2. Put child2_2 on top and child1_1 at the bottom.
When your jquery (or whatever) calls the absolute div, just set the according relative div (child1_1 or child2_2) with display:block AND visibility:hidden. The relative child will still be invisible but will make parent's div higher.
Feeela is right but you can get a parent div contracting or expanding to a child element if you reverse your div positioning like this:
.parent {
position: absolute;
/* position it in the browser using the `left`, `top` and `margin`
attributes */
}
.child {
position: relative;
height: 100%;
width: 100%;
overflow: hidden;
/* to pad or move it around using `left` and `top` inside the parent */
}
This should work for you.
This question was asked in 2012 before flexbox. The correct way to solve this problem using modern CSS is with a media query and a flex column reversal for mobile devices. No absolute positioning is needed.
https://jsfiddle.net/tnhsaesop/vjftq198/3/
HTML:
<div class="parent">
<div style="background-color:lightgrey;">
<p>
I stay on top on desktop and I'm on bottom on mobile
</p>
</div>
<div style="background-color:grey;">
<p>
I stay on bottom on desktop and I'm on top on mobile
</p>
</div>
</div>
CSS:
.parent {
display: flex;
flex-direction: column;
}
#media (max-width: 768px) {
.parent {
flex-direction: column-reverse;
}
}
With pure JavaScript, you just need to retrieve the height of your static position child element .child1 using the getComputedStyle() method then set that retrieve value as the padding-top for that same child using the HTMLElement.style property.
Check and run the following Code Snippet for a practical example of what I described above:
/* JavaScript */
var child1 = document.querySelector(".child1");
var parent = document.getElementById("parent");
var childHeight = parseInt(window.getComputedStyle(child1).height) + "px";
child1.style.paddingTop = childHeight;
/* CSS */
#parent { position: relative; width: 100%; }
.child1 { width: auto; }
.child2 { width: 145px; position: absolute; top: 0px; bottom: 0px; }
html, body { width: 100%;height: 100%; margin: 0; padding: 0; }
<!-- HTML -->
<div id="parent">
<div class="child1">STATIC</div>
<div class="child2">ABSOLUTE</div>
</div>
There's a very simple hack that fixes this issue
Here's a codesandbox that illustrates the solution: https://codesandbox.io/s/00w06z1n5l
HTML
<div id="parent">
<div class="hack">
<div class="child">
</div>
</div>
</div>
CSS
.parent { position: relative; width: 100%; }
.hack { position: absolute; left:0; right:0; top:0;}
.child { position: absolute; left: 0; right: 0; bottom:0; }
you can play with the positioning of the hack div to affect where the child positions itself.
Here's a snippet:
html {
font-family: sans-serif;
text-align: center;
}
.container {
border: 2px solid gray;
height: 400px;
display: flex;
flex-direction: column;
}
.stuff-the-middle {
background: papayawhip
url("https://camo.githubusercontent.com/6609e7239d46222bbcbd846155351a8ce06eb11f/687474703a2f2f692e696d6775722e636f6d2f4e577a764a6d6d2e706e67");
flex: 1;
}
.parent {
background: palevioletred;
position: relative;
}
.hack {
position: absolute;
left: 0;
top:0;
right: 0;
}
.child {
height: 40px;
background: rgba(0, 0, 0, 0.5);
position: absolute;
bottom: 0;
left: 0;
right: 0;
}
<div class="container">
<div class="stuff-the-middle">
I have stuff annoyingly in th emiddle
</div>
<div class="parent">
<div class="hack">
<div class="child">
I'm inside of my parent but absolutely on top
</div>
</div>
I'm the parent
<br /> You can modify my height
<br /> and my child is always on top
<br /> absolutely on top
<br /> try removing this text
</div>
</div>
I came up with another solution, which I don't love but gets the job done.
Basically duplicate the child elements in such a way that the duplicates are not visible.
<div id="parent">
<div class="width-calc">
<div class="child1"></div>
<div class="child2"></div>
</div>
<div class="child1"></div>
<div class="child2"></div>
</div>
CSS:
.width-calc {
height: 0;
overflow: hidden;
}
If those child elements contain little markup, then the impact will be small.
I had a similar problem.
To solve this (instead of calculate the iframe's height using the body, document or window) I created a div that wraps the whole page content (a div with an id="page" for example) and then I used its height.
"You either use fixed heights or you need to involve JS."
Here is the JS example:
---------- jQuery JS example--------------------
function findEnvelopSizeOfAbsolutelyPositionedChildren(containerSelector){
var maxX = $(containerSelector).width(), maxY = $(containerSelector).height();
$(containerSelector).children().each(function (i){
if (maxX < parseInt($(this).css('left')) + $(this).width()){
maxX = parseInt($(this).css('left')) + $(this).width();
}
if (maxY < parseInt($(this).css('top')) + $(this).height()){
maxY = parseInt($(this).css('top')) + $(this).height();
}
});
return {
'width': maxX,
'height': maxY
}
}
var specBodySize = findEnvelopSizeOfAbsolutelyPositionedSubDivs("#SpecBody");
$("#SpecBody").width(specBodySize.width);
$("#SpecBody").height(specBodySize.height);
There is a better way to do this now. You can use the bottom property.
.my-element {
position: absolute;
bottom: 30px;
}
This is very similar to what #ChrisC suggested. It is not using an absolute positioned element, but a relative one. Maybe could work for you
<div class="container">
<div class="my-child"></div>
</div>
And your css like this:
.container{
background-color: red;
position: relative;
border: 1px solid black;
width: 100%;
}
.my-child{
position: relative;
top: 0;
left: 100%;
height: 100px;
width: 100px;
margin-left: -100px;
background-color: blue;
}
https://jsfiddle.net/royriojas/dndjwa6t/
Also consider next approach:
CSS:
.parent {
height: 100%;
}
.parent:after {
content: '';
display: block;
}
Also since you are trying to reposition divs consider css grid
Absolute views position themselves against the nearest ancestor that isn't statically positioned (position: static), therefore if you want an absolute view positioned against a given parent, set the parent position to relative and the child to position to absolute
Try this, it was worked for me
.child {
width: 100%;
position: absolute;
top: 0px;
bottom: 0px;
z-index: 1;
}
It will set child height to parent height