Post on 27-Jun-2015
Class 2 Css: seleCtors, Classes & ids
Web Design, gR APH-327 1- 01
Instructor: Erika TarteRhode Island School of DesignWintersession 2011
webpage
In addition to content, webpages contain hidden information that help browsers interpret structure, meaning, style, interactions, etc.
Most of the visible information takes place in the body of the HTML document, while most of the hidden formation happens in the head of the HTML document.
Some information happens in external files, like CSS and JavaScript.
We link to these files in the head of the HTML document.
from web content to webpage
<html>
<head>
<title>Document Title</title>
</head>
<body>
...
</body>
</html>
basic html webpage
Css
CSS Stands for Cascading Style Sheet
Purpose
HTML tells us what to display CSS tells us how to display
Format
Simple text file Contains rules for displaying HTML
what’s css?
Inline Styles
defined within an individual tag with a lot of content starts to become inefficient
Internal styles
defined at the top of each individual page with a lot of pages, starts to become inefficient
External styles
defined once for your whole site all of your html pages link to the same file extremely efficient (and its what we’ll do in this class)
types of style sheets
Central definition of visual style make one change, the entire site is updated can be reused on any number of pages
Developers and designers can work independently
Same content can be restyled for lots of different media web print mobile phone iPod/iPhone/iPad
why external?
Cascading style rules are applied in order last definition takes precedence over the first
Order of priority 1 browser default lowest priority 2 external styles 3 internal styles 4 inline styles highest priority
characteristics
The only change in the HTML file is to add a line of code at the top:
<link rel=”stylesheet” type=”text/css” href=”styles.css” />
Tells browser to include a style sheet called styles.css
You can name the file anything you want (webstyles.css, printstyles.css, awesome.css)
Include the <link> tag just before the </head> tag in your HTML.
linking a css file to your html file
<html>
<head>
<title>Document Title</title>
<link rel=”stylesheet” type=”text/css” href=”styles.css” />
</head>
<body>
...
</body>
</html>
basic html webpage w/ link to css file
1 Create a text file and save it as styles.css
2 Add this line to your HTML, right before the </head> tag:
<link rel=”stylesheet” type=”text/css” href=”styles.css” />
3 Start writing CSS rules in your styles.css file
linking your first file demo
syntax
There are many style properties, don’t worry about memorizing them!
Keep a reference open while coding (www.w3schools.com)
be prepared...
selector = what you are defining
curly brackets { } = begin & end of rules for selector
property = set of display properties you can change
value = what you are changing the property to
semicolon ; = ends each rule
css syntax: vocabulary
selector { property: value; property: value; }
css syntax
selector { property: value; property: value; }
css syntax
selectoR is the html element these rules will change
selector { property: value; property: value; }
css syntax
PRoPeRt y is a display characteristic you are writing a rule for. Each selector can have multiple properties, and some selectors have very specif ic properties.
selector { property: value; property: value; }
css syntax
VAlue is the display characteristic that you want to apply to the property
sandwich { cheese: cheddar; bread: rye; condiment: mustard; condiment-style: spicy-brown; }
css syntax
h1 { font-family: Helvetica; font-size: 36px; font-weight:bold; text-transform:uppercase; color:#000000; }
css syntax
Classes & ids
These 2 attributes give you more control over the elements while using CSS
No inherent styles or properties
Different elements can share the same class
IDs are unique, and different elements can’t share them
html class & id attributes
<a href="http://google.com" class="button">Link</a>
<a href="http://google.com" id="button1">Link</a>
html class & id attributes
.button { font-size: 12px; color: #ff0000; text-decoration: none; }
#button1 { font-size: 12px; color: #ff0000; text-decoration: none; background-color: #ffff00; }
css class & id selectors
<a href="http://google.com" class="button">Link</a>
<a href="http://google.com" class=”button” id="button1">Link</a>
html class & id attributes
.button { font-size: 12px; color: #ff0000; text-decoration: none; }
#button1 { font-size: 12px; color: #ff0000; text-decoration: none; background-color: #ffff00; }
css class & id selectors
.button { font-size: 12px; color: #ff0000; text-decoration: none; }
#button1 { font-size: 12px; color: #ff0000; text-decoration: none; background-color: #ffff00; }
css class & id selectors
.button { font-size: 12px; color: #ff0000; text-decoration: none; }
#button1 { background-color: #ffff00; }
css class & id selectors
Color
rgb (red, green, blue) values 0 to 255 additive color black: 0,0,0 white: 255,255,255
hexadecimal or “hex" encoded value of rgb black: #000000 white: #FFFFFF
color values
rgb value
hexadecimal (hex) value
h1 { color: rgb(255,255,255); color: #ffffff; }
css property: color
h1 { color: #ffffff; background-color: #000000; }
css property: background-color
typography
Browsers only display fonts installed on the user’s computer (with some recent exceptions)
To define fonts, the font-family: css property is used
Designers use font-stacking to create prioritized lists of fonts to display
(A safety net, incase the first desired typeface is unavailable)
Start with a very specific typeface, move to a generic classification
fonts
h1 { color: #ffffff; background-color: #000000; font-family: Akkurat, Helvetica, sans-serif; }
css property: font-family
h1 { color: #ffffff; background-color: #000000; font-family: Akkurat, Helvetica, sans-serif; font-size: 72px; }
css property: font-size
h1 { color: #ffffff; background-color: #000000; font-family: Akkurat, Helvetica, sans-serif; font-size: 72px; font-weight: normal; }
css property: font-weight
h1 { color: #ffffff; background-color: #000000; font-family: Akkurat, Helvetica, sans-serif; font-size: 72px; font-weight: normal; letter-spacing: 4px; }
css property: letter-spacing
h1 { color: #ffffff; background-color: #000000; font-family: Akkurat, Helvetica, sans-serif; font-size: 72px; font-weight: normal; letter-spacing: 4px; text-transform: uppercase; }
css property: text-transform