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Tina Huynh
Tina Huynh

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The Trick with CSS Selectors

In CSS, selectors are patterns used to select the element(s) you want to style
w3schools

If you would like more information on CSS building blocks, MDN Web Docs and w3.org are great references.

parts of a CSS rule

Universial Selector

Selects every element in the document. Optionally, it can be restricted to a specific parent element.

* {}
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Type selectors

Selects a HTML element directly, such as "section", "a", "code", etc.

p {}
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Class selectors

Selects all elements given the class attribute.

.classname {}
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Optionally, can be used to select specific elements with multiple class attributes.

.class1.class2 {}
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ID selectors

Selects one specific elements corresponding to the given ID in the document.

#id {}
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Attribute selectors

Selects all elements given a specific attribute.

[attribute] {}
[attribute=value] {}
[attribute~=value] {}
[attribute|=value] {}
[attribute^=value] {}
[attribute$=value] {}
[attribute*=value] {}
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Grouping selectors

Selectors all the matching nodes

div,
span {}
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Combinators

web.dev has a detailed explanation of complex selectors.

Descendant combinators

Selects nodes descendant of the first element

div span {}
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Child combinators

Selectors nodes that are the direct child of the first element

div > p {}
```


#### [General sibling combinators](https://css-tricks.com/almanac/selectors/g/general-sibling/)
Selects all the elements of the second selector given that comes after the first element. The second element does **not** have to appear immediately after the first element.


```
div ~ a {}
```


#### [Adjacent sibling combinators](https://blog.kevinchisholm.com/css/combinators/general-sibling-vs-adjacent-sibling/)
Selects all the elements of the second selector given that *immediately* follows the first.


```
section + h2 {}
```



### Pseudo
#### [Pseudo classes](https://www.washington.edu/accesscomputing/webd2/student/unit3/module5/lesson3.html#:~:text=Overview,%2F*%20your%20style%20here%20*%2F%20%7D)
Selects elements based on the state information.


```
input:checked {}
input:indeterminate {}
input:invalid {}
input:enabled {}
input:focus {}
```


#### [Pseudo elements](https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-elements)
Selects entities that are not included in HTML


```
p::first-letter {}
p::first-line {}
p::before {}
p::after {}
```



Happy coding!

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Top comments (12)

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oricis profile image
Moisés Alcocer

Interesting, I didn't know some of the inputs pseudoclasses.
Maybe some comments, or link to get more information about some selectors could improve your work, for example, concrete use casses / browser support of the input:indeterminate selector here: w3schools.com/cssref/sel_indetermi...
or Warning with the *Universial Selector**, some possible performance issues asociated when use it!

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tmchuynh profile image
Tina Huynh

Great suggestion :) I will do my best to include more links in the future

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atulcodex profile image
🚩 Atul Prajapati 🇮🇳

Oh that's a detailed guide

Thanks for sharing, tina

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tmchuynh profile image
Tina Huynh

Glad I could be of help to you

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atulcodex profile image
🚩 Atul Prajapati 🇮🇳

keep doing :)

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thefrenchieweb profile image
Guillaume Ferber

Thank you for this great article.
A correction, though about the adjacent sibling combinators.
The correct syntax is:

section + h2 {}
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Keep bring more articles like that!

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tmchuynh profile image
Tina Huynh

Oops! Thank you so much for catching that

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tmchuynh profile image
Tina Huynh

The trick is to understand the fundamentals. With fundamentals, it's always easier to broaden one's horizons.

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ressenzo profile image
Renan Cossenzo

this is the kind of content that is basic, but VERY useful. thanks and congrats!

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tmchuynh profile image
Tina Huynh

Thanks :) glad I could provide useful information

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dionarodrigues profile image
Diona Rodrigues

Great tips, but I would recommend removing 'Column combinator' as this article is for beginners and this selctor is not working yet.

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tmchuynh profile image
Tina Huynh

Great note - I will definitely remove it