How to Override parent element css for child element - css

I have a site with multiple menus. I have defined enteire page content inside a div with a class container and applied bootstrap css styles (margin-left:auto and margin-right:auto etc.,) to make the page centered. Now elements in one of the file must start from extreme left side of the browser. Because of the css applied for parent i could not start the element from left side. I have applied margin-left with minus pixels to solve the issue. But when the browser window is small element is not completely visible in browser because of minus value applied for margin-left.
<div class="container" style="margin-left:auto;margin-right:auto">
<div id="start_from_left" style="margin-left=-50px"> </div>
</div>

if your tags have
style=""
that takes priority over anything else.
What you could try is the !important on your css tags, but its bad practice.
eg
margin-left:1px!important;
margin-right:0px!important;

You can have additional class for your container.
.container {
margin-left: auto;
margin-right: auto;
}
.container.wide {
margin-left: 0;
margin-right: 0;
}

Related

Can I somehow override a parents style for a specific child?

I'm working on an application with a main layout which has the bootstrap class "container-fluid".
<main class="container-fluid">
[....]
//a child div where I'd like to remove the parent's padding for this div
<div>
[....]
</div>
</main>
and as you probably know, container-fluid has padding in it, which is great, it's needed.
width: 100%;
padding-right: 15px;
padding-left: 15px;
margin-right: auto;
margin-left: auto;
However, inside one of the child components, I'd like the padding to be removed.
I made a not-so-pretty image to display what I mean, I hope it helps:
I know I could just put the component outside of the main tag, however, I really need it to be inside for a specific reason, and that's why I'm wondering if I can somehow remove the padding of a parent div for a single child div.
Thank you in advance!
nevermind, I suddenly figured it out :)
I put style="margin: -15px;" on the child div, and it worked wonderfully.

position:sticky is not working

I have this HTML code:
<div class="header">
<div class="desc">Description</div>
<div class="logo"><img src=""/></div>
<div class="navbar"></div></div>
.header has a height of 150px. .navbar has a height of 20px. When the user scrolls, I want .navbar to stick at the top. So I went to the CSS and set position:sticky and top:0. But this didn't work. I initially thought that firefox is not supporting position:sticky, but that's not the case because I was able to see a working demo of it. I googled about it but found nothing helpful. Anyone knows why this is not working?
Position sticky was not working for me due to the body element having overflow-x: hidden; set.
The 2 most common culprits why position: sticky; might not work are:
You haven't defined top: 0;, bottom: 0;, left: 0 or something similar
One of the parents of your sticky element has overflow (x or y) set to hidden, scroll or auto.
For me it was the first one.
It works fine if you move the navbar outside the header. See below. For the reason, according to MDN:
The element is positioned according to the normal flow of the document, and then offset relative to its flow root and containing block based on the values of top, right, bottom, and left.
For the containing block:
The containing block is the ancestor to which the element is relatively positioned
So, when I do not misunderstand, the navbar is positioned at offset 0 within the header as soon as it is scrolled outside the viewport (which, clearly, means, you can't see it anymore).
.navbar {
background: hotpink;
width: 100%;
height: 50px;
position: sticky;
top: 0;
}
.header {
height: 150px;
background: grey;
}
body {
height: 800px;
position: relative;
}
<div class="header">
<div class="desc">Description</div>
<div class="logo"><img src="" /></div>
</div>
<div class="navbar"></div>
To expand from the answers above and some information to make it work with flexbox parent and overflow other than visible (the examples below assume you use vertical - sticky with either top or bottom set to a certain value and position set to sticky):
The most frequent case is you have an ancestor element (not just immediate parent) with overflow property set to something other than visible and as a result there is no space is left to stick around.
To quickly find out if this is the case, you can run this script in the browser console (please make sure you change the .your-sticky-element class to your element's selector):
var stickyElement = document.querySelector('.your-sticky-element');
var parent = stickyElement.parentElement;
while (parent) {
var hasOverflow = getComputedStyle(parent).overflow;
if(hasOverflow != 'visible') {
console.log(hasOverflow, parent);
}
parent = parent.parentElement;
}
SOLUTION:
a) If you found there is overflow set, and you can remove it, this should solve it
b) If you have to keep your overflow setting, you have to make the parent element's height higher than the sticky element's height. If the parent element has no height or the sticky element fills up all the height, it means there is simply no place to stick within when the page is scrolled. It doesn't need to an explicit height (vertical), but you can inspect to see if your sticky element has extra space left after itself.
Parent is not higher than the sticky element to leave extra space. This particular case can be caused by different circumstances but the solution to this is the same above, please see 1.b
If your sticky element's parent is a flexbox (align-items has default value of normal) or grid, and if the sticky element itself doesn't have a proper align-self set, there will be no space left for the sticky element to hold when scrolling (for example, if it is align-self: stretch or auto [default value]). This is because the child element is stretched to fill up the height of the parent.
SOLUTION:
In this case, align-self: flex-start set for the sticky element can fix the problem because in the element will stand at the start, leaving extra space after itself.
Guide: There are much more complex circumstances both in the case of flexboxes and without it, but the general rule of thumb is your sticky element needs space within the parent to be sticky when scrolled.
Somehow your code only works when the .navbar element is not inside another container like the header. I moved it out and then it works fine. I created a codepen snippet for that, check it out
<header>
<div class="logo">Logo</div>
<div class="description"><div>Lorem ipsum dolor sit amet consectetur adipisicing elit. Quo, veritatis.</div></div>
</header>
<div class="navbar">
<ul>
<li>navitem1</li>
<li>navitem2</li>
<li>navitem3</li>
<li>navitem4</li>
</ul>
</div>
Right now position:sticky is supported quite good as you can see on canIuse. Of course IE currently has no support but the new Edge version will bring full support for this! I found some interesting articles about this topic:
Working demo (chrome,firefox 👍) https://codepen.io/simevidas/pen/JbdJRZ
Caniuse refernce: http://caniuse.com/#search=sticky
sticky article on MDN including latest browser support table https://developer.mozilla.org/en-US/docs/Web/CSS/position#Sticky_positioning
But there are good news on the horizon. I think better browser support will follow the next time.
Adding more content after nav inside header provides sticky behavior, but only for a moment - if the user scrolls down too much, nav will disappear with header, since it can't jump out below header's bottom border.
Thus, the only solution with pure CSS is to put nav inside element that is partially visible even after the user scrolls to the bottom of the page (directly inside body or inside some sort of container that spans to the bottom of the page or at least to the footer).
If this solution is not possible, the other way is to use JavaScript. Before transitioning to CSS, I used the following code (found similar jQuery solution somewhere long time ago, don't remember where, so the credit goes to the anonymous author; Vanilla JS can be easily obtained from this):
$(document).ready(function () {
var sticky_navigation_offset_top = $('nav').offset().top;
var sticky_navigation = function () {
var scroll_top = $(window).scrollTop();
if (scroll_top > sticky_navigation_offset_top) {
$('nav').css({
'position': 'fixed',
'top': 0,
'left': 0,
'right': 0,
'margin-left': 'auto',
'margin-right': 'auto'
});
} else {
$('nav').css({
'position': 'relative'
});
}
};
sticky_navigation();
$(window).scroll(function () {
sticky_navigation();
});
});
Looks like if you try to set sticky a container which has many children nodes inside, instead of them being wrapped in a div, and the parent of sticky container is flex, then it will not sticky. Just wrap the childs in a div fixed it for me.
Your HTML code as it is and write CSS class for navigation bar:
.header {
height: 150px;
background-color: #d1d1d1;
}
.navbar {
background: #999;
border-bottom: 1px solid #333;
border-top: 1px solid #333;
color: #FFF;
margin: 0;
padding: 2px 0 0 12px;
position: sticky;
top: -1px;
}
<div class="header">
<div class="desc">Description</div>
<div class="logo"><img src="" /></div>
<div class="navbar"></div>
</div>
Hope this will help
Met some not evident behaviour of horizontal sticky: if width is 100%, then sticky does not work. Width should be less, then container size.
My sticky header would only partly work ... after a couple of scrolls it would disappear but would work initially
It appears the problem was that I had the parent set to height 100%.
I didn't actually need this as the body one was enough so I removed and it and all was good.. sticks forever
Although this now breaks my footer from staying on the bottom when their is no content!
No huge compromises of the HTML structure need to be made to fix this issue. Simply add display: inline; to all of the sticky element's parents up until you get to the element you wish the sticky element to stick to.
Just to add something to #user56reinstatemonica8 great point...
If immediate parent of sticky node has display: flex sticky positioning could not work.
My guess is that culprit is align-items: stretch as default.
In a flex-direction: row scenario, align-items: stretch let children's height grow so that they are equal height.
So, to overcome this and make sticky work as expected with display: flex you can:
define align-items as center | start | baseline to immediate parent that has display: flex.
define align-self as center | start | baseline to sticky node.
define an explicit height to sticky node.

Escape the bounds of a div container

Alright, I understand that the purpose of a DIV is to contain its inner elements - I didn't want to upset anyone by saying otherwise. However, please consider the following scenario:
My web page (which only takes up a width of 70% of the entire page) is surrounded by a container (a div). However, under my navigation bar which is at the top of the page, I would like to create w banner that takes up 100% of the width of the entire page (which means it will have to extend outside the bounds of its container as the container is only taking up 70% of the page's width).
This is the basic idea that I am trying to accomplish: http://www.petersonassociates.biz/
Does anyone have any suggestions for how I could accomplish this? I'd appreciate any help.
Evan
If you just want the background of the element to extend across the whole page this can also be achieved with negative margins.
In a nutshell (correction from comment):
.bleed {
padding-left: 3000px;
margin-left: -3000px;
padding-right: 3000px;
margin-right: -3000px;
}
That gives you horizontal scroll bars which you remove with:
body {overflow-x: hidden; }
There is a guide at http://www.sitepoint.com/css-extend-full-width-bars/.
It might be more semantic to do this with psuedo elements: http://css-tricks.com/full-browser-width-bars/
EDIT (2019):
There is a new trick to get a full bleed using this CSS utility:
width: 100vw;
margin-left: 50%;
transform: translateX(-50%);
I guess all solutions are kind of outdated.
The easiest way to escape the bounds of an element is by adding:
margin-left: calc(~"-50vw + 50%");
margin-right: calc(~"-50vw + 50%");
discussion can be found here and here. There is also a nice solution for the upcoming grid-layouts.
If I understood correctly,
style="width: 100%; position:absolute;"
should achieve what you're going for.
There are a couple of ways you could do this.
Absolute Positioning
Like others have suggested, if you give the element that you want to stretch across the page CSS properties of 100% width and absolute position, it will span the entire width of the page.
However, it will also be situated at the top of the page, probably obscuring your other content, which won't make room for your now 100% content. Absolute positioning removes the element from the document flow, so it will act as though your newly positioned content doesn't exist. Unless you're prepared to calculate exactly where your new element should be and make room for it, this is probably not the best way.
Images: you can also use a collection of images to get at what you want, but good luck updating it or making changes to the height of any part of your page, etc. Again, not great for maintainability.
Nested DIVs
This is how I would suggest you do it. Before we worry about any of the 100% width stuff, I'll first show you how to set up the 70% centered look.
<div class="header">
<div class="center">
// Header content
</div>
</div>
<div class="mainContent">
<div class="center">
// Main content
</div>
</div>
<div class="footer">
<div class="center">
// Footer content
</div>
</div>
With CSS like this:
.center {
width: 70%;
margin: 0 auto;
}
Now you have what appears to be a container around your centered content, when in reality each row of content moving down the page is made up of a containing div, with a semantic and descriptive class (like header, mainContent, etc.), with a "center" class inside of it.
With that set up, making the header appear to "break out of the container div" is as easy as:
.header {
background-color: navy;
}
And the color reaches to the edges of the page. If for some reason you want the content itself to stretch across the page, you could do:
.header .center {
width: auto;
}
And that style would override the .center style, and make the header's content extend to the edges of the page.
Good luck!
The more semantically correct way of doing this is to put your header outside of your main container, avoiding the position:absolute.
Example:
<html>
<head>
<title>A title</title>
<style type="text/css">
.main-content {
width: 70%;
margin: 0 auto;
}
</style>
</head>
<body>
<header><!-- Some header stuff --></header>
<section class="main-content"><!-- Content you already have that takes up 70% --></section>
<body>
</html>
The other method (keeping it in <section class="main-content">) is as you said, incorrect, as a div (or section) is supposed to contain elements, not have them extend out of bounds of their parent div/section. You'll also face problems in IE (I believe anything 7 or below, this might just be IE6 or less though) if your child div extends outside the parent div.

My link is not recognized by its parent <div>. why?

I have a <a> in a <div> but the <div> doesn't recongize the <a> and adjust and increase its height to accomodate the link.
Check it out my html/css here: http://jsfiddle.net/RjfVN/2/
That is because your section-link class has float: left;
You need to clear the float. To do this you can add a div directly after the closing </a> like:
<div style="clear: left;"></div>
Or
<div class="clearfix"></div>
And add .clearfix{ clear: both; } to your css so you can reuse it.
Put overflow:auto to your #main.
Yep, your link is using float:left. There are a few ways to fix it.
Have something after the link (like #footer for instance) clear: left (or both).
Float the #main container div as well, or give it position: absolute
Add overflow: auto to the #main container div.
However, in cases 2 & 3 you will need to set the width of the container as well, since it won't have the initial 100% width that it's using. Also, in Internet explorer, setting the width is actually required for the overflow to have any effect because it forces the container to hasLayout.

Why do my icons line up top-to-bottom instead of flowing left-to-right in a DIV layout?

I have these 3 icons enclosed in separate DIVs all of which are enclosed within a single DIV:
<div id="icons">
<div id="divtxt" class="divicon">
<img src="/icons/text.png" id="icontxt" class="icon"/>
</div>
<div id="divpdf" class="divicon">
<img src="/icons/pdf.png" id="icondoc" class="icon"/>
</div>
<div id="divrtf" class="divicon">
<img src="/icons/rtf.png" id="iconrtf" class="icon"/>
</div>
</div>
I set some simple styles but can't figure out why these images are lining up top-to-bottom instead of left-to-right:
div#icons
{
width:200px;
height: 100px;
}
div.divicon
{
margin: 0 0 0 0;
padding: 0 0 0 0;
border: 0 0 0 0;
}
Any suggestions would be appreciated.
And now for something a bit more comprehensive:
You look like you just want a row of icons. Using your HTML, you would need to float the divs containing the icons in order for them to be next to each other. The reason why you need to float is because a div is a block level element (as opposed to inline) which means that nothing can exist in the horizontal space next to it.
You can achieve this effect by adding a float: left; rule to div.divicon
Floating does two things: it takes the block element out of the page flow allowing other elements to exist next to it (or flow around it) and it reduces the width of the box to fit the content. As far as the parent is concerned, a floated element has no height. To illustrate this, just try giving #icons a background color or border. You will notice that it won't show up - or show up as a 1px line.
In order for the parent to recognise the height of the floated element you need to tell the parent that overflow should be hidden with this rule:
#icons { overflow:hidden; }
This also works in IE however not always, so sometimes you might need to set a height or width or do a zoom:1 which tends to fix a lot of IE bugs (look up "hasLayout bug" if you want more info).
Now for a different solution:
You look like you just want a row of icons. Unless theres a reason for the images to be surrounded in a div (and in your example there is none) I would suggest to you to do something like this:
<div id="icons">
<img src="/icons/text.png" id="icontxt" />
<img src="/icons/pdf.png" id="icondoc" />
<img src="/icons/rtf.png" id="iconrtf" />
</div>
#icons { /* rules for our container go here */ margin:0; padding:0; /* etc... */ }
#icons img { /* rules for your icons */ border:none; margin:0 2px; /* etc... */ }
I have removed the redundant divs and the redundant class attribute on the images. Since images are inline elements you wont need to screw around with floats and you wont have any extra divs that may cause divitis a degenerative HTML disease that affects many websites and spreads through bad advice. Remember, only use what you need - don't use it just because its there.
Hope this helps,
Darko
You need a
float: left;
in your div#icons.
div is a block level element. So the default behavior is to layout one below the other, unless you float them like Robert suggested.

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