CODEWITHSUNDEEP
css
Jordan Lev
Jordan Lev

Reputation:

How do I prevent CSS inheritance?

I have a hierarchical navigation menu in my sidebar that uses nested lists (<ul> and <li> tags). I am using a pre-made theme that already has styles for list items, but I want to alter the style for the top-level items but NOT have it apply to the sub-items. Is there an easy way to apply styles to the top-level list item tag WITHOUT having those styles cascade down to its children list items? I understand that I can explicitly add overriding styles to the sub-items but I'd really like to avoid having to duplicate all of that style code if there is an easy way to just say "apply these styles to this class and DO NOT cascade them down to any children elements". Here is the html I'm using:

<ul id="sidebar">
  <li class="top-level-nav">
    <span>HEADING 1</span>
    <ul>
      <li>sub-heading A</li>
      <li>sub-heading B</li>
    </ul>
  </li>
  <li class="top-level-nav">
    <span>HEADING 2</span>
    <ul>
      <li>sub-heading A</li>
      <li>sub-heading B</li>
    </ul>
  </li>
</ul>

So the CSS has styles for #sidebar ul and #sidebar ul li already, but I'd like to add additional styles to #sidebar .top-level-nav that do NOT cascade down to its sub-children. Is there any way to do this simply or do I need to rearrange all of the styles so the styles that were on #sidebar ul are now specific to certain classes?

Upvotes: 125

Views: 182747

Answers (13)

Jorge Epu&#241;an
Jorge Epu&#241;an

Reputation: 760

here's an live example using cascade, initial and all property:

div {
  border: 1px solid red;
  margin: 10px;
}

div p {
  color: red;
}

.initial {
  border-color: initial;
}

.initial p {
  color: initial;
}

.asterisk,
.asterisk * {
  border-color: initial;
  color: initial;
}

.all,
.all * {
  all: initial
}

https://jsbin.com/cosabusiwi/1/edit?html,css,output

Upvotes: 1

Apostolos Dedeloudis
Apostolos Dedeloudis

Reputation: 9

You can wrap the element that you don't want to inherit any styles in a div with no style.

Something like this:

<div style='all: revert !important;'>
  Your content here
</div>

Upvotes: 1

Sampath Liyanage
Sampath Liyanage

Reputation: 4896

You may use Shadow Dom which is a new feature provided by browsers. Browser support is also pretty decent for the date.

Documentation: https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_shadow_DOM

Upvotes: 2

Boldewyn
Boldewyn

Reputation: 82734

There is a property called all in the CSS3 inheritance module. It works like this:

#sidebar ul li {
  all: initial;
}

As of 2016-12, all browsers but IE/Edge and Opera Mini support this property.

Upvotes: 61

Stickers
Stickers

Reputation: 78686

Short answer is: No, it's not possible to prevent CSS inheritance. You can only override the styles that are set on the parents. See the spec:

Every element in an HTML document will inherit all inheritable properties from its parent except the root element (html), which doesn’t have a parent. -W3C

Apart from overriding every single inherited property. You can also use initial keyword, e.g. color: initial;. It also can be used together with all, e.g. all: initial;, that will reset all properties at once. Example:

.container {
  color: blue;
  font-style: italic;
}
.initial {
  all: initial;
}
<div class="container">
  The quick brown <span class="initial">fox</span> jumps over the lazy dog
</div>

Browser support tables according to Can I use...

  • all (Currently no support in both IE and Edge, others are good)
  • initial (Currently no support in IE, others are good)

You may find it useful by using direct children selector > in some cases. Example:

.list > li {
  border: 1px solid red;
  color: blue;
}
<ul class="list">
  <li>
    <span>HEADING 1</span>
    <ul>
      <li>sub-heading A</li>
      <li>sub-heading B</li>
    </ul>
  </li>
  <li>
    <span>HEADING 2</span>
    <ul>
      <li>sub-heading A</li>
      <li>sub-heading B</li>
    </ul>
  </li>
</ul>

The border style has been applied only to the direct children <li>s, as border is an non-inherited property. But text color has been applied to all the children, as color is an inherited property.

Therefore, > selector would be only useful with non-inherited properties, when it comes to preventing inheritance.

Upvotes: 6

Silviu Postavaru
Silviu Postavaru

Reputation: 1794

You either use the child selector

So using

#parent > child

Will make only the first level children to have the styles applied. Unfortunately IE6 doesn't support the child selector.

Otherwise you can use 

#parent child child

To set another specific styles to children that are more than one level below.

Upvotes: 79

user2985029
user2985029

Reputation:

You can use the * selector to change the child styles back to the default

example

#parent {
    white-space: pre-wrap;
}

#parent * {
    white-space: initial;
}

Upvotes: 35

stevenvh
stevenvh

Reputation: 3139

You don't need the class reference for the lis. Instead of having CSS like

li.top-level-nav { color:black; }

you can write

ul#sidebar > li { color:black; }

This will apply the styling only to lis that immediately descend from the sidebar ul.

Upvotes: 2

Tuğrul
Tuğrul

Reputation: 372

Wrapping with iframe makes parent css obsolete.

Upvotes: 12

user2848911
user2848911

Reputation: 23

For example if you have two div in XHTML document.

<div id='div1'>
    <p>hello, how are you?</p>
    <div id='div2'>
        <p>I am fine, thank you.</p>
    </div>
</div>

Then try this in CSS.

#div1 > #div2 > p{
    color: red;
}

affect only 'div2' paragraph.

#div1 > p {
    color: red;
}

affect only 'div1' paragraph.

Upvotes: 2

Neil Richards
Neil Richards

Reputation: 200

You could use something like jQuery to "disable" this behaviour, though I hardly think it's a good solution as you get display logic in css & javascript. Still, depending upon your requirements you might find jQuery's css utils make life easier for you than trying hacky css, especially if you're trying to make it work for IE6

Upvotes: 1

Scott Vander Molen
Scott Vander Molen

Reputation: 6439

As of yet there are no parent selectors (or as Shaun Inman calls them, qualified selectors), so you will have to apply styles to the child list items to override the styles on the parent list items.

Cascading is sort of the whole point of Cascading Style Sheets, hence the name.

Upvotes: 39

Matthew Vines
Matthew Vines

Reputation: 27561

just set them back to their defaults in the "#sidebar ul li" selector

Upvotes: 0

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