Exam 98-383: Introduction to Programming using HTML and CSS/Understand CSS Fundamentals
This lesson covers CSS fundamentals, including inline styles, internal style sheets, external style sheets, rule sets, and industry best practices.[1]
Readings
[edit | edit source]- Mozilla: CSS Basics
- Mozilla: Cascade and Inheritance
- CSS Tricks: Methods to Organize CSS
- HTML Goodies: Testing CSS Against Multiple Browsers
Activities
[edit | edit source]Analyze the impact of using inline styles, internal style sheets, and external style sheets
[edit | edit source]Includes when to use inline styles; when to use internal style sheets; when to use external style sheets; precedence when using a combination of inline styles and style sheets.
Inline Styles
[edit | edit source]Inline CSS has the format:[2]
<element style="property: value;">content</element>
Example:
<p style="color: blue;">This text is blue.</p>
Internal Style Sheets
[edit | edit source]Internal CSS has the format:[3]
<head>
<style>
selector {property: value;}
</style>
</head>
Example:
<head>
<style>
p {color: blue;}
</style>
</head>
External Style Sheets
[edit | edit source]External CSS is specified using a link element:[4]
<head>
<link href="path/to/file.css" rel="stylesheet" type="text/css">
</head>
External CSS files have the format:[5]
selector {property: value;}
which may also be written as:
selector {
property: value;
}
or
selector
{
property: value;
}
Examples:
h1 {color: red;}
h2 {
color: green;
}
h3
{
color: black;
}
Precedence
[edit | edit source]Precedence (the cascade) is based on:[6]
- Importance
- Specificity
- Source Order
Importance has the highest precedence, but its use is not recommended.[7]
Example:
p {
color: red !important;
}
After importance, the more specific a selector is, the higher the precedence will be.[8]
- inline (higher)
- ID (#)
- Class (.)
- Element tag (lower)
If completing rules have the same importance and specificity, rules defined later override earlier rules.[9] When multiple external CSS style sheets are linked, or internal and external style sheets are used, the order in which the links and internal styles are defined determines precedence.[10]
Construct and analyze rule sets
[edit | edit source]Includes valid syntax for the CSS rule set; selectors, including class, id, elements and pseudo-class.
- A CSS pseudo-class is a keyword added to a selector that specifies a special state of the selected element(s).[11][12][13]
Examples:
/* all */
* {
font-family: Arial, Helvetica, sans-serif;
}
/* class */
.class {
color: green;
}
/* id */
#id {
background-color: red;
}
/* element */
p {
color: blue;
}
/* multiple elements */
h1, h2 {
color: blue;
}
/* elements inside elements */
div p {
font-weight: bold;
}
/* child elements */
div > p {
font-style: italic;
}
/* pseudo-classes */
a:link {
color: #FF0000;
}
a:hover {
color: #FF00FF;
}
a:active {
color: #0000FF;
}
a:visited {
color: #00FF00;
}
Construct well-formed style sheets that conform to industry best practices
[edit | edit source]Includes reusing rules and rule sets; commenting; testing on multiple browsers; web safe fonts.
Reuse
[edit | edit source]Rules and rule sets may be reused in CSS and in HTML.
Examples:
h1, p {
color: blue;
}
.border {
border: thin solid blue;
}
.red {
color: red;
}
<h1>Blue Heading</h1>
<p class="border">Blue paragraph with border</p>
<p class="red border">Red paragraph with border</p>
Comments
[edit | edit source]CSS comments are added using /* comment */
syntax.[14]
Examples:
/* unvisited link */
a:link {
color: #FF0000;
}
/* visited link */
a:visited {
color: #00FF00;
}
Testing
[edit | edit source]Test CSS using the W3C CSS Validator service, and test using multiple browsers.
Visit CanIUse to check browser compatibility with different HTML and CSS features.
Web Safe Fonts
[edit | edit source]font-family
[edit | edit source]There are only a certain number of fonts that are generally available across all systems.[15][16]
Examples:
body {
font-family: Arial, Helvetica, sans-serif;
}
h1 {
font-family: "Times New Roman", Times, serif;
}
.monospace {
font-family: "Courier New", Courier, monospace;
}
font
[edit | edit source]The font
CSS property is a shorthand for font-style
, font-variant
, font-weight
, font-stretch
, font-size
, line-height
, and font-family
. If used, it must include values for <font-size>
and <font-family>
.[17]
Examples:
p {
font: 1.2em sans-serif
}
p {
font: 80% sans-serif
}
p {
font: bold italic large serif
}
See Also
[edit | edit source]References
[edit | edit source]- ↑ Microsoft: Exam 98-383 Introduction to Programming using HTML and CSS
- ↑ Wikipedia: Cascading Style Sheets
- ↑ Wikipedia: Cascading Style Sheets
- ↑ Wikipedia: Cascading Style Sheets
- ↑ Wikipedia: Cascading Style Sheets
- ↑ Mozilla: Cascade and Inheritance
- ↑ Mozilla: Cascade and Inheritance
- ↑ Mozilla: Cascade and Inheritance
- ↑ Mozilla: Cascade and Inheritance
- ↑ W3Schools: CSS How To
- ↑ W3Schools: CSS Selectors Reference
- ↑ Mozilla: Pseudo-classes
- ↑ W3Schools: CSS Pseudo-classes
- ↑ W3Schools: CSS Pseudo-classes
- ↑ Mozilla: Fundamental text and font styling
- ↑ W3Schools: Web Safe Fonts
- ↑ Mozilla: font