CSS3 Properties & Selectors

Welcome!

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Download workshop files

If you have not already downloaded the files for this workshop - please download them at gdiboulder.com/css-properties

Slides are available at materials.gdiboulder.com. Click on "CSS Properties & Selectors".

Digital copy of the Selectors Cheat Sheet.

Thanks to our sponsor:

Meet your instructor: Cara Jo Miller

• Co-founder: Girl Develop It Boulder
• Lead Designer: Simple Energy
• E-mail: carajo@girldevelopit.com
• Twitter: @corrinajo
• Lover of all things glitter

But first - let's have a recap.

CSS Recap

The CSS rule:

selector {
  property: value;
  property: value;
}

Different properties & values:

body {
  color: yellow;
  background-color: black;
}
p {
  width: 70%;
  padding: 10px;
  margin: auto;
}
h1 {
  font-size: 12px;
  border-bottom: 1px solid #ccc;
}

Really basic selectors

HTML:

  
item 1
  
item 2
  
item 3
 

CSS:

#myID: ID
.myClass: Class
ul/li: Elements

Basic CSS Specificity

ul        { font-weight: bold; }
li        { color: magenta; }
.myClass  { color: red; }
#myID     { color: blue; font-weight: normal; font-style: italic;}

• Item 1
• Item 2
• Item 3

Open basic-selectors.html in your browser.

Modify the CSS to see how Specificity works.

CSS Specificity

Specificity is the means by which a browser decides which property values are the most relevant to an element and gets to be applied. Specificity is only based on the matching rules which are composed of selectors of different sorts.

In case of specificity equality, the latest declaration found in the CSS is applied to the element.

Say you have this:

.favorite {
   color: red;
}
.favorite {
   color: black;
}

The color will be black because it comes last in the cascade

Later on we declare this

ul#summer-drinks li.favorite {
  color: green;
  font-weight: bold;
}

The color will now be green, because this is more specific that the previous declaration.

Finally we get really specific

html body div#pagewrap ul#summer-drinks li.favorite {
  color: magenta;
  font-weight: bold;
}

The color will now be magenta, because this is the most specific of them all.

But what if it's important?

.favorite {
  color: orange !important;
  font-weight: bold !important;
}

The !important declaration is like a ninja and will force itself over all other declarations.

This should be used sparingly

CSS Specificity Resources

An illustrated SpeciFISHity chart

Another illustrated chart

CSS Tricks: Specifics on CSS Specificity

Specificity Calculator

Let's talk about Selectors!

Many Selectors!!

*                   :before               :root                 :enabled
E                   ::before              :last-child           :disabled
.class              ::selection           :only-child           :checked
#id                 :after                :nth-child()          :indeterminate
E F                 ::after               :nth-last-child()     :default
E > F               :first-letter         :first-of-type        :valid
E + F               ::first-letter        :last-of-type         :invalid
E[attribute]        :first-line           :only-of-type         :in-range
E[attribute=value]  ::first-line          :nth-of-type()        :out-of-range
E[attribute~=value] E[attribute^=value]   :nth-last-of-type()   :required
E[attribute|=value] E[attribute$=value]   :empty                :optional
:first-child        E[attribute*=value]   :not()                :read-only
:lang()             E ~ F                 :target               :read-write

Checkout caniuse.com for compatability across browsers.

Relational Selectors & Combinators

Advanced ways to target elements using basic selectors.

Attribute Selectors

element[attribute]

Select elements containing the named attribute

img[alt] {}
  <img src="image.jpg" alt="accessible">     
  <img src="image.jpg" title="inaccessible">  
form [type] {} 
  <input type=date>  
  <select>

Older Attribute Selectors

E[attr]

Element E that has the attribute attr with any value.

a[href] {
  background: pink;
} 
/* Styles all links with the attribute 'href' */

E[attr="val"]

Element E that has the attribute attr with the exact, case-sensitive if attribute is case sensitive, value val.

a[href="http://girldevelopit.com"] {
  background: magenta; font-weight: bold;
} 
/* Styles all links to http://girldevelopit.com */

Older Attribute Selectors

E[attr|=val]

Element E whose attribute attr has a value val or begins with val- ("val" plus "-").

p[lang|="en"] 
  {background: url(icon-flag.png);
} 
/* Syles elements <p lang="en-us"> OR <p lang="en-uk"> */

E[attr~=val]

Element E whose attribute attr has within its value the space-separated full word val.

a[title~=more] {
  color: orange;
} 
/* Styles links that have a title that contain 'more' 
surrounded by spaces. <a title="want more info about this?"> */

CSS3 Attribute Selectors

E[attr^=val]

Element E whose attribute attr starts with the value val.

a[href^=mailto] {background-image: url(emailicon.gif);}
a[href^=http]:after {content: " (" attr(href) ")";}

E[attr$=val]

Element E whose attribute attr ends in val .

a[href$=pdf] {background-image: url(pdficon.gif);}
a[href$=pdf]:after {content: " (PDF)";}

E[attr*=val]

Element E whose attribute attr matches val anywhere within the attribute.

Note: Multiple attributes work! a[title][href]

Attribute Selectors

To review

input[placeholder] {}         E:[attr] 
input[type=email] {}          E:[att=val]
abbr[title~=unicorn] {}       E:[att~=val]
abbr[title|=en] {}            E:[att|=val]
a[href^=mailto] {}            E:[att^=val] 
a[href$=pdf]{}                E:[att$=val] 
abbr[title*=unicorn] {}       E:[att*=val]

Don't forget, you can use Attribute Selectors in Media Queries

@media print{
  abbr[title]:after { 
    content: "(" attr(title) ")";
  }
  a[href^=http]:after { 
    content: "(" attr(href) ")";
  }
}

Using Attribute Selectors

Open attribute-selectors.html in your web browser.

Change the CSS and see what happens.

UI pseudo-classes

Based on the current state of the UI

:enabled
:disabled
:checked
:focus

input[type=checkbox]:checked + label {
  color: red;
}

Form related UI pseudo-classes

valid           :in-range
:invalid        :out-of-range
:required       :read-only
:optional       :read-write
:default

Examples:

input:valid { border: 1px solid green;}
input:invalid { border: 1px solid red;}
input:required {border-width: 5px;}
input:optional {border-width: 10px;}
input:out-of-range { background-color: pink;}
input:in-range { background-color:lightgreen;}

Using UI Selectors

Open ui-selectors.html in your web browser.

Change the CSS and click the checkboxes to see how the form UI changes.

Structural Selectors

:nth-child()          :first-of-type
:nth-last-child()     :last-of-type
:nth-of-type()        :only-child 
:nth-last-of-type()   :only-of-type
:first-child*         :root
:last-child           :empty
                      :not(:empty)

Target elements on the page based on their relationships to other elements in the DOM.

Updates dynamically if page updates.

Reduced need for extra markup, classes and IDs

Using Structural Selectors

Open structural-selectors.html in your browser.

Experiment with targetting different element on the page with Structural Selectors.

nth pseudo-classes

Target element or elements based on argument passed to the selector

:nth-child(3n) 
:nth-last-child(odd) 
:nth-of-type(5) 
:nth-last-of-type(3n+1)

:nth-of-type(even)
:nth-of-type(odd)
:nth-of-type(an+b)

Getting crazy with Structural Selectors!

li:first-child,
li:last-child {
  font-weight: bold;
}
li:first-of-type,
li:last-of-type{
  text-decoration:line-through;
}
li:nth-child(even) {
  background-color: #CCC;
}
li:nth-child(3) {
  color: #CCC;
}
li:nth-of-type(odd) {
  background-color: #FFF;
}
li:nth-of-type(4n) {
  color: hsl(205, 87%, 50%);
}
li:nth-of-type(3n-1) {
  text-align: right;
}

nth-child to the nth-degree of confusion

Nth-child can be very confusing. Here's some resources:

CSS Tricks: How nth-child works

Mastering the nth-child

Nth-child browser support

Use nth-child

Open nth-child-selectors.html in your browser.

Change the values of the nth-child to see what cells change colors

Go crazy!

Open flag.html and see how crazy you can get with nth-child selectors.

Misc. Pseudo Classes

These should be familar.

:link
:visited
:hover
:active
:focus

:not

:empty

:lang
:target

Using the :not selector

The :not selector creates an argument using a simple selector and then matches elements on the page that do not match that element.

Open not-selector.html in your browser

Try using our previous selectors to styles things (or not!).

Pseudo Elements

Pseudo classes select elements that already exist

Pseudo Elements create fake elements you can style.

::first-letter

p:first-of-type::first-letter {
  position: relative;
  top: 8px;
  float: left;
  font-size: 3em;
  line-height: 1;
  color: magenta;
  padding: 0 4px 2px 0;
  font-weight: bold;    
}

Open first-letter.html to play with this pseudo-element.

Using ::after & ::before

You can use ::after and ::before in combination with 'content' to add some elements to your page without having to edit the HTML

.triangle-border {
  position:relative;
  padding:15px;
  margin:1em 0 3em;
  border:5px solid #5a8f00;
  color:#333;
  background:#fff;
}
.triangle-border::before {
  content:"";
  position:absolute;
  bottom:-20px;
  left:40px;
  border-width:20px 20px 0;
  border-style:solid;
  border-color:#5a8f00 transparent;
}
.triangle-border::after {
  content:"";
  position:absolute;
  bottom:-13px;
  left:47px;
  border-width:13px 13px 0;
  border-style:solid;
  border-color:#fff transparent;
}

Open after-before.html to see this in action.

Icon fonts use ::before

Icon fonts use ::before to insert a unicode character with 'content' that is associated with a glyph in that font.

.icon-search:before {
  content: "\f002";
}
.icon-envelope-o:before {
  content: "\f003";
}
.icon-heart:before {
  content: "\f004";
}

::beore and :before are often interchangable.

Properties

Vendor Prefixes

Don't forget, when using fancy CSS3 properties you need to add the vendor prefixes so all browsers can play.

  selector {
  property: value;
  -webkit-property: value;
  -moz-property: value;
  -ms-property: value;
  -o-property: value;
}

div {
  border-radius: 3px;
  -webkit-border-radius: 3px;
  -moz-border-radius: 3px;
  -ms-border-radius: 3px;
  -o-border-radius: 3px;
}

Text Stroke

div {
  -webkit-text-fill-color: black;
  -webkit-text-stroke-color: magenta;
  -webkit-text-stroke-width: 0.00px; 
}

Opacity with RGBA values

  color: rgba(255, 0, 0, 0.75); 
  background: rgba(0, 0, 255, 0.75); 

Hue Saturation Luminance

color: hsla(
  128, 
  74%, 
  33%, 
  1.00 
        

CSS Gradients

background-image: linear-gradient(to bottom, #00abeb 0%, #fff 50%,
                            #66cc00 50%, #fff 100%);

background-image: radial-gradient(center, circle cover, red, #000 40%);
                                                        

CSS3 Shadows

text-shadow: 
  rgba(64, 64, 64, 0.5) 
  0px 
  0px 
  0px; 

box-shadow: 
  rgba(0, 0, 128, 0.25) 
  0px 
  0px 
  0px; 
            

Web Fonts

@font-face {
    font-family: 'alpha_echoregular';
    src: url('fonts/alpha_echo-webfont.eot');
    src: url('fonts/alpha_echo-webfont.eot?#iefix') format('embedded-opentype'),
         url('fonts/alpha_echo-webfont.woff') format('woff'),
         url('fonts/alpha_echo-webfont.ttf') format('truetype'),
         url('fonts/alpha_echo-webfont.svg#alpha_echoregular') format('svg');
    font-weight: normal;
    font-style: normal;

}

.special-header {
  font-family: 'alpha_echoregular';
}

Finding Web Fonts

• Google Web Fonts
• TypeTester
• TypeKit
• OpenFont Library
• Typotheque
• whatthefont.com
• Font Squirrel's Font-face generator

Transition

#box-1, #box-2  {
  background: magenta;
}
#box-1:hover, #box-2:hover {
  background: lime;
}
#box-2 {
  -webkit-transition: background 1s ease-in-out;
  -moz-transition: background 1s ease-in-out;
  -ms-transition: background 1s ease-in-out;
  -o-transition: background 1s ease-in-out;
  transition: background 1s ease-in-out;
}

Transformations

Hover over me:

-webkit-transform: rotateY(45deg);
-webkit-transform: scaleX(25deg);
-webkit-transform: translate3d(0, 0, 90deg);
-webkit-transform: perspective(500px)

#threed-example {
  -webkit-transform: rotateZ(5deg);

  -webkit-transition: -webkit-transform 2s ease-in-out;
}
#threed-example:hover {
  -webkit-transform: rotateZ(-5deg);
}

Animations

@-webkit-keyframes pulse {
from {
 opacity: 0.0;
 font-size: 100%;
}
to {
 opacity: 1.0;
 font-size: 200%;
}
}

div {
-webkit-animation-name: pulse;
-webkit-animation-duration: 2s;
-webkit-animation-iteration-count: infinite;
-webkit-animation-timing-function: ease-in-out;
-webkit-animation-direction: alternate;
}

That's it!

Use your new powers for good!

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