When I want to apply a certain style to a div (specially using bootstrap 3), I create my own class like this:
.myClass {
width: 30%;
padding-right: 0px;
}
<div class="myClass"></div>
But sometimes the div style is overwritten by the bootstrap classes or another inherited properties (I don't understand completely the inheritance in CSS3), but if I apply directly in the div:
<div style="width: 30%;padding-right: 0px;"></div>
2 ways to force CSS on an element in this case :
You have you custom CSS located in a local .css file : put the <link> tag for this custom stylesheet after the Bootstrap css file.
Set the CSS rule !important after each properties so they will get an extra authority upon others
CSS inheritance
.myClass is less than div.myClass which is less than body div.myClass.
The Bootstrap is using usually more than one identifier. Like .ourClass.theirClass.yourClass which is hard to overwrite. Inspect your element in your browser to see the inheritance and try to overwrite it the css way before using any !important attributes.
The last rule defining a style of the element will be aplied to it.
So if you have various stylesheets in your page, the order of the files should be in the order you want them to be applied. example:
<link rel="stylesheet" href="style.css">
<link rel="stylesheet" href="secondStyle.css">
Every style rule(not an entire block) that is written in the second file will be the definitive one in the website.
the same rule apllies within files, for example:
.ClassOne {
color: red;
}
... othes styling ...
.classOne {
color: Black;
}
In this case the color in the browser will be Black because it was the last one and it overwrites the first one.
There is another rule that can affect styling - The more specific rule will be the definitive one, example:
.one .two .three {
color: red;
}
.two .three {
color: blue;
}
.one .three {
color: green;
}
<div class="one">
<div class="two">
<div class="three">
some text
</div>
</div>
</div>
Question: In which color will the text show?
Answer: red.
Why? because in the case above, we call the .three element in a more specific way when we declared the red color.
check it here:
https://jsfiddle.net/wxaw3205/
The same example with more elements:
https://jsfiddle.net/wxaw3205/1/
The last way is using the !important declaration, it provides a way for You to give a CSS value more weight than it naturally has.
For the last example, lets assume that we have the same html markup of the example above, which will be the color now?
.one .two .three {
color: red;
}
.two .three {
color: blue;
}
.one .three {
color: green !important;
}
Answer: green.
Link to live example: https://jsfiddle.net/wxaw3205/2/
And just a little tip: never style the element using the style="" attribute, unless you have too! and either the !important.
Most of the time when you have to use them its because you'r stylesheet needs to be reordered.
That's all, I hope it helped you understand.
Related
I have a situation in which i want to change the color of my box with the on hover from the container i which this box is found.
I found out how to do this through a different question here on stackoverflow How to affect other elements when a div is hovered
But now i want to change the color of my box to a third option when i hover the box itself.
This is and exaple html with css.
<body>
<div class="container">container
<div class="box">
box</div>
</div
</body>
</html>
and the css.
.container{
background-color:grey;
height: 100px;
width:100px;
}
.container:hover .box{
background-color: aqua;
}
.box{
background-color: blue;
width:50px;
height: 50px;
}
.box:hover{
background-color: white;
}
This is the way i tried to do it but this does not work. The first steps works but i can't get the third color.
Simply change
.box:hover{
background-color: white
}
TO
.container:hover>.box:hover{
background-color: white
}
And try it here: http://jsfiddle.net/czmzxd6j/
You'll have to create a more specific selector.
You're setting .container:hover .box {...} which is more specific than .box:hover.
Your issue will be resolved if you use .container:hover .box:hover {...} because this is more specific than the one with just the .box at the end.
Using the direct-child selector isn't the way nor is !important (sorry guys, no offence but it's just not the correct approach here.)
CSS is all about overwriting and that is why these things can be nasty sometimes.
Whenever something doesn't get applied correctly just think to yourself for 3 seconds: "Are there any other selectors that manipulate this element that could be more specific?".
With the general selector .box:hover any box anywhere in the DOM will have that hover as long as it has the .box class however this is not true for the other selector including .container:hover .box:hover.
That selector is actually more specific due to the fact that now only .box elements within the .container elements get the hover.
By specifying the general selector instead of one that is atleast as specific it will simply be overwritten by the more specific one, that's why you need to re-add .container:hover to the selector.
I hope it makes sense to you.
Good luck!
try this:
.box:hover{
background-color: white !important;
}
you can see it here: https://jsfiddle.net/fusg2o3f/
If I have two different stylesheets and a class name that is being shared on both of them, something like this:
Home.css:
.myClass{
color: red;
}
Sales.css:
.myClass{
color: blue;
}
And now I would like to be able to to something like this:
<div class = "Sales.css.myClass" >....</div> <!--Here I am calling the blue color from Sales.css-->
Is there any way to specify from what stylesheet is the class I want to call?
CSS file priority depend on the sequence of files you have defined in the header, having the last one picked up, unless your rule has higher specificity.
However, what you are trying to do is a bad practice, leading to reduced readability and maybe conflicts.
Why don't you just put your rule to different rules in each file:
/*Home.css*/
.myHomeClass{
color: red;
}
/*Sales.css*/
.mySalesClass{
color: blue;
}
And then put the one you want to your element?
<div class = "mySalesClass" >....</div>
Simple CSS rule: later rule extends previous rules for same class.
That is
.myClass {
color: red;
font-size: 14px;
}
.myClass {
color: blue;
}
.myClass will be blue 14px font size.
Also you specify .myClass in CSS but your class in HTML Sales.css.myClass and that's different classes. Do you mean Sales css myClass?
I have been searching the web to try and find an answer to my question but cant seem to find a direct answer. I use article classes a lot in my work, however never really needed to know whether they load in order i.e what comes first on the page.
Example
<div id="example" article class="example1 example2 example3">
Here's the div.
</div>
Additionally I would like to ask, if I set a background in example 1 and set a background in example two, would the background of example 1 be there underneath example two. I guess I am asking if it would be like stacking divs on top of one another.
The reason I ask is because I have an article class with a background of an ajax loader. However I need to load an image directly ontop of the ajax loader. Its my idea of making a budget preloader without all the scripting hastle.
Thanks again!
What you're asking about is the order of precedence of applying CSS rules. Simplified:
It does not matter in which order you specify the classes on an element (class="foo bar baz").
It does matter in which order you write the CSS declarations in your CSS file.
foo { ... }
bar { ... }
baz { ... }
Later rules override earlier rules.
You are applying properties specified in these CSS rules to an element. An element can only have one such property, they do not "stack". If two CSS rules specify the same property, later rules overwrite that property on the element.
Example:
<div class="baz bar foo">
.foo {
color: blue;
border: 1px solid green;
}
.bar {
color: black;
border-color: orange;
}
.baz {
color: red;
margin: 10em;
}
Again, the order of the classes in the class="..." attribute is irrelevant. All three classes are applied to the element. First, .foo, then .bar, then .baz. The element will have the following properties, which are the result of merging the above rules:
color: red; # from .baz
border-color: orange; # from .bar
border-style: solid; # from .foo
border-width: 1px; # from .foo
margin: 10em; # from .baz
(Note that rule precedence is actually a little more complex than that and actually depends on the specificity of the selector, but the above goes for equally specific selectors.)
I write a html element as below ::
<div class="box"> Foo box </div>
and write css like
.box {
width: 400px;
height: 40px;
color: red;
text-align: center;
}
or
div.box {
width: 400px;
height: 40px;
color: red;
text-align: center;
}
I want to ask that how the both css for box class is different than each other.
The difference is that in the first class you tell that all element (div, p, span ...) with class box have that attribute.
Like this:
<span class="box">test</span>
<div class="box">test</div>
<p class="box">test</p>
The second class means that only div with class box has that attribute
Only this elements get second class:
<div class="box">test</div>
The selector before the class specify which type of elements can take this class
One very important difference between div.box and simply .box is in something called selector specificity. It is a set of rules which defines which selector gets more weight once the browser starts going through all the selectors that potentially have influence on a particular element.
What this means is easily demonstrated in the following example (DEMO)
We have a simple div containing some text.
<div class="box">
Zarro boogs found!
</div>
Now we add some CSS selectors to the example.
div.box {
padding:0.8em;
background: #bd0000;
color: #fff;
}
.box {
color: #bd0000;
}
One of the most basic rules of CSS is that selectors can be redefined in a way that whatever definition comes last and has influence on a particular element its the one that is going to be used (the sole exception being when using !important which always takes precedence).
Now in the above example redefining the .box class selector should actually hide the text but instead its still visible. How is that possible if we said that latter rules always take precedence? Its because the div.box rule has a higher specificity that .box since it actually gets points for containing both an element (div) and a class selector (.box) in its selector declaration (div.box).
Of course the div.box rule will be applied only on a div element but since class selectors are often reusable pieces of code there is plenty of situations when they are used on divs.
Although the rules in the official W3 specification are not that hard to understand they are sometimes pretty hard to remember. That's why I would like to recommend an excellent article on CSS selector specificity which can be found here.
In my opinion selector specificity is by far the most important thing to master when it comes to tracing inheritance problems with CSS stylesheets.
.box means any element having class box.
Example:
<div class="box">...</div>
<section class="box">...</section>
<span class="box">...</span>
div.box means only div element having class box.
Example:
<div class="box">...</div>
I have a case where I have a .menu within a #header and when I accessed .menu's children via a css selector like .menu a, it is using the #header a instead.
I was expecting the .menu a to override the #header a as it is closer to the a element. Why isn't this happening? I'm assuming it has with it being a class compared to an id based on the example below.
In the example, is there a good way override #red span css within .blue span without otherwise restricting the parent style?
By "good way" I suppose I mean flexible. For example .blue could be an element created by a php framework that is used in many places (possibly not within an id styled parent element, or possibly within a parent styled on a different id).
Here is an example. All except #green will still be red:
HTML:
<div id="red">
<span>red</span>
<div class="blue">
<span>blue(class) - should be blue</span>
</div>
<div id="green">
<span>green(id) - should be green</span>
</div>
<div class="green">
<span>green(class) - should be green</span>
</div>
<div>
<span>no child div style - should still be red</span>
</div>
</div>
CSS:
#red span {
color: red;
}
.blue span {
color: blue;
}
.green, #green span {
color: green;
}
The priority of applying a CSS rule (without !important) is:
Number of IDs in the selector. If draw,
Number of attributes and classes. If draw,
names or pseudo-elements. If draw,
last declaration on the CSS file. This, of course, never draws.
Since #red span has an ID, and .green doesn't have any, #red span applies.
For further explanation of which CSS rule is apply first, check this nice article on smashing magazine
To work around, you can use a more specific rule. This way it gets tie on number one, but since it have extra classes, your rule wins due the number two.
Selector specificity dictates that id had priority over class. Even though the blue class is after red in the Cascade, red takes priority because of specificity. You can use the Selector #red .blue span if needed
the simplest and cleanest:
http://jsfiddle.net/f4ke2/7/
#red {
color: red;
}
.blue span {
color: blue;
}
.green, #green span {
color: green;
}
OR What if you do this? :)
#red > span {
color: red;
}
OR
#red .blue span {color: blue;}
OR
.blue span {
color: blue !important;
}
OR for "flexibility"
#red .blue span, .blue span, #someotherID .blue span {color: blue;}
OR something as horrid as this
var id = $("#red");
id.addClass(id.attr("id")).removeAttr("id");
If you are using style sheets (in a framework or otherwise) that assign properties to elements by class, i.e. using class selectors, you simply have to take this into account when writing other CSS rules. So this is a matter of disciplined coding (HTML and CSS), not about using some trick to get rid of normal CSS principles.
Basically, set properties only on those elements that you want to have affected, without using selectors with too wide coverage. Say, if you want to set the text inside some element red, set color: red on that element only, not on its descendants, unless you really want to override whatever settings they might have.
For example, if there is a style sheet with .foo { color: blue }, then this will affect any element in class foo, unless overridden by another rule, as per the CSS cascade. So if you don’t want it to be overridden in a situation like <div id=xxx>...<span class=foo>...</span>...</div>, you just can’t set #xxx span { color: red }, because then you would override the rule, by virtue of a more specific selector. Using #xxx { color: red } would be safe in this sense, since the span (having its color set) will not inherit its parent’s color.
Using !important as in .foo { color: blue !important } might seem to solve the problem, but !important makes style sheets difficult to manage and maintain. It also creates problems when you need a tool for overriding the effect of specificity but can’t, because you’ve already fired the weapon. The rule .foo { color: blue !important } is not effective against #xxx span { color: red !important }.