Cascade Style Sheet Demo W3Schools.com: ISYS 350

Cascading Style Sheets Cascading Style Sheets (CSS) is a mechanism for adding style (e.g., fonts, colors, spacing) to Web documents. A style sheet consists of a list of style rules. Each rule or rule-set consists of one or more selectors, and a declaration block.

CSS Rule Syntax A CSS rule has two main parts: a selector, and one or more declarations:

A CSS declaration always ends with a semicolon, and declaration groups are surrounded by curly brackets. Example: p { color:red; text-align:center; }

Typical Properties of Style background-color – Color – color:red font – font-family:courier Font-size – font-size:300% text-align – text-align:center

Three Ways to Insert CSS External style sheet Internal style sheet Inline style

External Style Sheet An external style sheet can be written in any text editor. It should be saved with a.css extension. An external style sheet is ideal when the style is applied to many pages. A web page must link to the style sheet using the tag. The tag goes inside the head section:

CSS MIME Type Multipurpose Internet Mail Extensions (MIME) is an Internet standard of content type system. CSS MIME type: – text/css Example: referencing a CSS file using the element inside the head section

Internal Style Sheet An internal style sheet should be used when a single document has a unique style. You define internal styles in the head section of an HTML page, by using the tag, like this: hr {color:sienna;} p {margin-left:20px;} body {background-image:url("images/back40.gif");} Note: Do not add a space between the property value and the unit (such as margin-left:20 px). The correct way is: margin-left:20px

Inline Styles To use inline styles you use the style attribute in the HTML tag. Example: This is a paragraph. An inline style loses many of the advantages of style sheets by mixing content with presentation. Use this method sparingly!

HTML Element as Selector Apply to all elements of a specific type: – H1 { color: blue; } – p {color:red;text-align:center;}

Creating an External Stylesheet File 1. Right-Click Web Pages Folder, then select New/ Cascade Style Sheet 2. Define rules 3. Add a reference to the style sheet file H1 { color: blue; } H3 {color:green;} H6 {color:red;} p {color:red;text-align:center;} body {background-color:aqua;}

External Stylesheet Example head> TODO supply a title This is h1 text This is h3 text This is h6 text This is h1 text again This is h3 text again This is h6 text again This is the P tag data

Example: Internal stylesheet TODO supply a title H1 { color: blue; } H3 {color:green;} H6 {color:red;} p {color:red;text-align:center;} body {background-color:aqua;} This is h1 text This is h3 text This is h6 text This is h1 text again This is h3 text again This is h6 text again This is the P tag data

ID as a selector The id selector is used to specify a style for a single, unique element identified by the id attribute of the HTML element. The selector is with a preceding '#': Example: – A HTML element : – The style rule is: #mycontent { width: 450px; margin: 0 auto; padding: 15px; background: white; border: 2px solid navy; }

Class As Selector The class selector is used to specify a style for a group of elements. The class selector uses the HTML class attribute to set a particular style for many HTML elements with the same class. The class selector is defined with a "."

Examples of Class Selector Example 1: All HTML elements with class="center" will be center-aligned: – HTML: Center-aligned heading – Style: with a preceding “.”.center{ text-align:center; } Example 2: In the example below, all p elements with class="center" will be center-aligned: – p.center {text-align:center;}

Example This is h1 text This is h3 text This is h6 text This is h1 text again This is h3 text again This is h6 text again This is the P tag data This is the 2nd P tag data.center{ text-align:center; } p.left{text-align:left;}

The CSS Box Model All HTML elements can be considered as boxes. In CSS, the term "box model" is used when talking about design and layout. The CSS box model is essentially a box that wraps around HTML elements, and it consists of: margins, borders, padding, and the actual content.

box model

Explanation of the different parts of a box Margin - Clears an area around the border. The margin does not have a background color, it is completely transparent Border - A border that goes around the padding and content. The border is affected by the background color of the box Padding - Clears an area around the content. The padding is affected by the background color of the box Content - The content of the box, where text and images appear

Example width:250px; padding:10px; border:5px solid gray; margin:10px; The total width of the element in the example is 300px: 250px (width) + 20px (left + right padding) + 10px (left + right border) + 20px (left + right margin) = 300px

Example: Define a box for a P tag: p{color:red;text-align:center; width:250px; padding:10px; border:5px solid gray; margin:10px; }

HTML Element Object Properties: className property style property Assuming we have two classes: –.evenColor {color:red;} –.oddColor {color:black;} Example of assigning className value dynamically using code. var row = table.insertRow(rowCount); if(count % 2 == 0){ row.className = "evenColor"; } else{ row.className = "oddColor"; } Example of assigning style property using code: var boxFV=document.getElementById('FV'); fv=myPV*Math.pow(1+myRate,myYear); if (fv>1000) boxFV.style.backgroundColor = "red"; else boxFV.style.backgroundColor = "green";

Loan Affordability Analysis

HTML Code Loan Affordability Analysis Enter Loan: Enter Rate: Enter Term: Enter Affordable payment: Payment is:

computePmt() function computePmt(){ Loan=parseFloat(document.getElementById("Loan").value); Rate=parseFloat(document.getElementById("Rate").value); Term=parseFloat(document.getElementById("Term").value); Afford=parseFloat(document.getElementById("Afford").value); Pmt=(Loan*Rate/12)/(1-Math.pow(1+Rate/12,-12*Term)); var boxPmt=document.getElementById("Pmt"); if (Pmt>Afford) boxPmt.style.backgroundColor="red"; else boxPmt.style.backgroundColor="green"; boxPmt.value=Pmt.toFixed(2); }

CSS File div { width: 450px; margin: 0 auto; padding: 15px; background: aqua; border: 2px solid navy; } p {font-weight:bold;}

Positioning Elements can be positioned using the top, bottom, left, and right properties. However, these properties will not work unless the position property is set first. – Fixed: An fixed element will not move even if the window is scrolled – Relative: – absolute #mycontent { position: absolute;left:100px;top:100px; width: 450px; margin: 0 auto; padding: 15px; background: white; border: 2px solid navy; }

Without Positioning #div1 { width: 100px; margin: 0 auto; padding: 15px; background: blue; border: 2px solid navy; } #div2 { width: 100px; margin: 0 auto; padding: 15px; background: red; border: 2px solid navy; } This is div 1 This is div 2

With positioning #div1 { position: absolute;left:100px;top:100px; width: 100px; margin: 0 auto; padding: 15px; background: blue; border: 2px solid navy; } #div2 { position: absolute;left:200px;top:100px; width: 100px; margin: 0 auto; padding: 15px; background: red; border: 2px solid navy; } This is div 1 This is div 2

Pseudo Class Selector : pseudo-classes are used to add special effects to some selectors. For example, change color when mouse is over the element, a:hover {color:#FF00FF;} table:hover {color:red;} td:hover {color:blue;} p:hover{color:blue;} See list of pseudo-classess such as link, visited, focus, etc.:

function showTable(){ value=eval(document.depForm.pValue.value); life=eval(document.depForm.pLife.value); depreciation = value / life; var table = document.getElementById('depTable'); var totalDepreciation=0; for(var i = table.rows.length - 1; i > 0; i--) { table.deleteRow(i); } for (count = 1; count <= life; count++) { var rowCount = table.rows.length; var row = table.insertRow(rowCount); if(count % 2 == 0){ row.className = "evenColor"; }else{ row.className = "oddColor"; } var cell0 = row.insertCell(0); cell0.innerHTML=count; var cell1 = row.insertCell(1); cell1.innerHTML="$" + value.toFixed(2); var cell2 = row.insertCell(2); cell2.innerHTML="$" + depreciation.toFixed(2); totalDepreciation += depreciation; var cell3 = row.insertCell(3); cell3.innerHTML="$" + totalDepreciation.toFixed(2); value -= depreciation; }

Body Section Straight Line Depreciation Table Enter Property Value: Enter Property Life_: Year Value at BeginYr Dep During Yr Total to EndOfYr

CSS File #content { width: 650px; margin: 0 auto; padding: 15px; background: aqua; border: 2px solid navy; } table:hover {color:blue;} td:hover {color:blue;} table { border:1px solid green; margin: 0 auto; }.evenColor {color:red;}.oddColor {color:black;} p { font-size: 200; font-weight: bold; text-align: center; text-decoration: underline; }

Adding New Elements to HTML Creating an HTML Element document.createElement("myHero") myHero { display: block; background-color: #ddd; padding: 50px; font-size: 30px; } My First Hero

XML with Stylesheet Example My Favorite Book John Smith Peter Chen $45.00 This is a grerat book My Second Favorite Book Adam Smith $25.00 This is a second great book

Style Sheet Example btitle{ display:block; font-family: Aerial, Helvetica; font-weight: bold; font-size: 20pt; color: #9370db; text-align: center; } ISBN{ display:block; font-family: Aerial, Helvetica; font-weight: bold; font-size: 12pt; color: #c71585; text-align: left; } Authors{ display:inline; font-family: Aerial, Helvetica; font-style: italic; font-size: 10pt; color: #9370db; text-align: left; } Price{ display:block; font-family: Aerial, Helvetica; font-size: 12pt; color: #ff1010; text-align: left; } Description { display:block; font-family: Aerial, Helvetica; font-size: 12pt; color: #ff1010; text-align: left; }

CSS Font-Size: em vs. px vs. pt vs. percent An em is equal to the current font-size, for instance, if the font-size of the document is 12pt, 1em is equal to 12pt. Ems are scalable in nature, so 2em would equal 24pt,.5em would equal 6pt, etc. Generally, 1em = 12pt = 16px = 100%