Art 344 Quiz 2: CSS basics part 3/3
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box model
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2CSS Tutorial ❮ HomeNext ❯ CSS is a language that describes the style of an HTML document. CSS describes how HTML elements should be displayed. This tutorial will teach you CSS from basic to advanced. Examples in Each Chapter This CSS tutorial contains hundreds of CSS examples. With our online editor, you can edit the CSS, and click on a button to view the result. CSS Example body { background-color: lightblue; } h1 { color: white; text-align: center; } p { font-family: verdana; font-size: 20px; } Try it Yourself » Click on the "Try it Yourself" button to see how it works. Start learning CSS now! CSS Examples Learn from over 300 examples! With our editor, you can edit the CSS, and click on a button to view the result. Go to CSS Examples! CSS Templates We have created some responsive W3.CSS templates for you to use. You are free to modify, save, share, and use them in all your projects. Free CSS Templates! CSS Exercises and Quiz Test Test your CSS skills at W3Schools! Start CSS Quiz! Start CSS Exercises! CSS References At W3Schools you will find complete CSS references of all properties and selectors with syntax, examples, browser support, and more. CSS Properties Reference CSS Selectors Reference CSS Functions Reference CSS Animatable Reference CSS Aural Reference CSS Units CSS Color Reference CSS Default Values CSS Browser Support CSS Exam - Get Your Diploma! W3Schools Certification W3Schools' Online Certification The perfect solution for professionals who need to balance work, family, and career building. More than 10 000 certificates already issued! Get Your Certificate » The HTML Certificate documents your knowledge of HTML. The CSS Certificate documents your knowledge of advanced CSS. The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM. The jQuery Certificate documents your knowledge of jQuery. The PHP Certificate documents your knowledge of PHP and SQL (MySQL). The XML Certificate documents your knowledge of XML, XML DOM and XSLT. The Bootstrap Certificate documents your knowledge of the Bootstrap framework.
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4CSS Introduction ❮ PreviousNext ❯ What is CSS? CSS stands for Cascading Style Sheets CSS describes how HTML elements are to be displayed on screen, paper, or in other media CSS saves a lot of work. It can control the layout of multiple web pages all at once External stylesheets are stored in CSS files CSS Demo - One HTML Page - Multiple Styles! Here we will show one HTML page displayed with four different stylesheets. Click on the "Stylesheet 1", "Stylesheet 2", "Stylesheet 3", "Stylesheet 4" links below to see the different styles: Why Use CSS? CSS is used to define styles for your web pages, including the design, layout and variations in display for different devices and screen sizes. CSS Solved a Big Problem HTML was NEVER intended to contain tags for formatting a web page! HTML was created to describe the content of a web page, like: <h1>This is a heading</h1> <p>This is a paragraph.</p> When tags like <font>, and color attributes were added to the HTML 3.2 specification, it started a nightmare for web developers. Development of large websites, where fonts and color information were added to every single page, became a long and expensive process. To solve this problem, the World Wide Web Consortium (W3C) created CSS. CSS removed the style formatting from the HTML page! CSS Saves a Lot of Work! The style definitions are normally saved in external .css files. With an external stylesheet file, you can change the look of an entire website by changing just one file!
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6CSS Syntax and Selectors ❮ PreviousNext ❯ CSS Syntax A CSS rule-set consists of a selector and a declaration block: CSS selector The selector points to the HTML element you want to style. The declaration block contains one or more declarations separated by semicolons. Each declaration includes a CSS property name and a value, separated by a colon. A CSS declaration always ends with a semicolon, and declaration blocks are surrounded by curly braces. In the following example all <p> elements will be center-aligned, with a red text color: Example p { color: red; text-align: center; } Try it Yourself » CSS Selectors CSS selectors are used to "find" (or select) HTML elements based on their element name, id, class, attribute, and more. The element Selector The element selector selects elements based on the element name. You can select all <p> elements on a page like this (in this case, all <p> elements will be center-aligned, with a red text color): Example p { text-align: center; color: red; } Try it Yourself » The id Selector The id selector uses the id attribute of an HTML element to select a specific element. The id of an element should be unique within a page, so the id selector is used to select one unique element! To select an element with a specific id, write a hash (#) character, followed by the id of the element. The style rule below will be applied to the HTML element with id="para1": Example #para1 { text-align: center; color: red; } Try it Yourself » Note: An id name cannot start with a number! The class Selector The class selector selects elements with a specific class attribute. To select elements with a specific class, write a period (.) character, followed by the name of the class. In the example below, all HTML elements with class="center" will be red and center-aligned: Example .center { text-align: center; color: red; } Try it Yourself » You can also specify that only specific HTML elements should be affected by a class. In the example below, only <p> elements with class="center" will be center-aligned: Example p.center { text-align: center; color: red; } Try it Yourself » HTML elements can also refer to more than one class. In the example below, the <p> element will be styled according to class="center" and to class="large": Example <p class="center large">This paragraph refers to two classes.</p> Try it Yourself » Note: A class name cannot start with a number! Grouping Selectors If you have elements with the same style definitions, like this: h1 { text-align: center; color: red; } h2 { text-align: center; color: red; } p { text-align: center; color: red; } It will be better to group the selectors, to minimize the code. To group selectors, separate each selector with a comma. In the example below we have grouped the selectors from the code above: Example h1, h2, p { text-align: center; color: red; } Try it Yourself » CSS Comments Comments are used to explain the code, and may help when you edit the source code at a later date. Comments are ignored by browsers. A CSS comment starts with /* and ends with */. Comments can also span multiple lines: Example p { color: red; /* This is a single-line comment */ text-align: center; } /* This is a multi-line comment */ Try it Yourself » Test Yourself with Exercises!
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8CSS How To... ❮ PreviousNext ❯ When a browser reads a style sheet, it will format the HTML document according to the information in the style sheet. Three Ways to Insert CSS There are three ways of inserting a style sheet: External style sheet Internal style sheet Inline style External Style Sheet With an external style sheet, you can change the look of an entire website by changing just one file! Each page must include a reference to the external style sheet file inside the <link> element. The <link> element goes inside the <head> section: Example <head> <link rel="stylesheet" type="text/css" href="mystyle.css"> </head> Try it Yourself » An external style sheet can be written in any text editor. The file should not contain any html tags. The style sheet file must be saved with a .css extension. Here is how the "mystyle.css" looks: body { background-color: lightblue; } h1 { color: navy; margin-left: 20px; } 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; Internal Style Sheet An internal style sheet may be used if one single page has a unique style. Internal styles are defined within the <style> element, inside the <head> section of an HTML page: Example <head> <style> body { background-color: linen; } h1 { color: maroon; margin-left: 40px; } </style> </head> Try it Yourself » Inline Styles An inline style may be used to apply a unique style for a single element. To use inline styles, add the style attribute to the relevant element. The style attribute can contain any CSS property. The example below shows how to change the color and the left margin of a <h1> element: Example <h1 style="color:blue;margin-left:30px;">This is a heading</h1> Try it Yourself » Tip: An inline style loses many of the advantages of a style sheet (by mixing content with presentation). Use this method sparingly. Multiple Style Sheets If some properties have been defined for the same selector (element) in different style sheets, the value from the last read style sheet will be used. Example Assume that an external style sheet has the following style for the <h1> element: h1 { color: navy; } then, assume that an internal style sheet also has the following style for the <h1> element: h1 { color: orange; } If the internal style is defined after the link to the external style sheet, the <h1> elements will be "orange": Example <head> <link rel="stylesheet" type="text/css" href="mystyle.css"> <style> h1 { color: orange; } </style> </head> Try it Yourself » However, if the internal style is defined before the link to the external style sheet, the <h1> elements will be "navy": Example <head> <style> h1 { color: orange; } </style> <link rel="stylesheet" type="text/css" href="mystyle.css"> </head> Try it Yourself » Cascading Order What style will be used when there is more than one style specified for an HTML element? Generally speaking we can say that all the styles will "cascade" into a new "virtual" style sheet by the following rules, where number one has the highest priority: Inline style (inside an HTML element) External and internal style sheets (in the head section) Browser default So, an inline style (inside a specific HTML element) has the highest priority, which means that it will override a style defined inside the <head> tag, or in an external style sheet, or a browser default value.
Is HTML5 a programming language? Nowadays, we can use HTML5 to make apps, as in android, in firefox os, iPhone, Blackberry and others. But, I heard that HTML is a Markup language, not for programming. Even with App features, HTML continues to being only a markup language?
It's certainly more than just a markup language, since it also defines interfaces for e.g. history and storage APIs useable in JavaScript. But those are only descriptions, much like the DOM API, it's not a language
