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Intermediate CSS. Spans & Divs , Ids & Classes. <span> and <div>. The <span> tag is generally used to apply a style to inline text:
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Intermediate CSS Spans & Divs , Ids & Classes
<span> and <div> • The <span> tag is generally used to apply a style to inline text: <p><span class="foo">This text is rendered as foo-style</span> and this is not. The <div> tag is generally used to apply a style to a block of text, which can also include other HTML elements: • Difference? • The <div> tag also acts as a paragraph break. You use the span tag when you want to modify text without having it break from the paragraph.
<span> and <div> • The <span> tag is generally used to apply a style to inline text: <p><span class="foo">This text is rendered as foo-style</span> and this is not. The <div> tag is generally used to apply a style to a block of text, which can also include other HTML elements: • Difference? • The <div> tag also acts as a paragraph break. You use the span tag when you want to modify text without having it break from the paragraph.
class and id • Just like you can base some style on Tags (also known as Elements) you can also add your own attributes • class and id • NOTE: when naming your classes and Ids its best to name them in a way that describes function not presentation class=“header” makes more sense than class=“bluetext” example: <table class=“red3”>…
The classattribute in HTML • In HTML class is used to define a related group of HTML elements on a page. • Elements using a class can be of any type. Could be a <p>, another could be an <img> or a <td> from a table. • In your HTML you define your class by adding it like you would any HTML attribute with an equals sign and quotations. • <body> <h2 class=“q2”>This is my header </h2> <p class=“r3”> We will be meeting on Weds at <span class=“q2”> 8:00am</span> </p> • </body>
The class selector in CSS • The class selector is defined by a period (.) .q2 {color: blue;} .r3 {font-family: Arial;} NOTE: CASE MATTERS!!! Selectors/tags/attributes are CASE sensitive!! So .qball is not the same as .qBall
The class selector in CSS • You can combine element (aka tag) selectors with a class selector. The result only those members of the class (which are of that particular element) span.q2 {color: blue;} p.r3 {font-family: Arial;}
The idattribute in HTML • Similar to the class attribute • Can be set on nearly any tag and can be used as a CSS selector • Much more restricted • Only one tag on a page can be given that specific id. • NOTE: id attribute’s value must begin with a letter (but can be followed by numbers, periods, underscores, hyphens, or colons)
id selectors in CSS • id selectors are indicated by a hash or pound sign (#) in CSS stylesheets. • Example #menu { font-size: large; }
id vs class • A class selector is more flexible, can do anything an id selector can do and more. • If you want to reuse the style, you can use classes. • Cannot do this with an id selector because an id value MUST be unique. Only one element/tag on a page can have that id .
Combining same selector • Two rules that share the same selector can be combined by listing their declarations within the curly braces p { background-color: #434567; font-family: sans-serif; color: white; } p { background-color: #434567; font-family: sans-serif; } p { color: white; }
Combining different selectors • If two rules have the same declarations (but different selectors) you can combine them also as long as they are separated with a comma , p { color: #434567; } #address{ color: #434567; } p , #address { color: #434567; }
<span> and <div> • The <span> tag is generally used to apply a style to inline text: <p><span class="foo">This text is rendered as foo-style</span> and this is not. The <div> tag is generally used to apply a style to a block of text, which can also include other HTML elements: • Difference? • The <div> tag also acts as a paragraph break. You use the span tag when you want to modify text without having it break from the paragraph.
CSS shorthand • You can list all the font properties in one list. • Must be in a specific order • Selector { font: style variant weight size family; border: top right bottom left; } • Any values that aren’t listed are set to their default values.
Universal Selector • Applues to all tags and content within a page and is represented by an asterisk (*) • *{color: red;} • Has limited compatability with explorer 4.0 and Netscape 4.0
Pseudo-selectors • Psuedo-Selector – a selector based on a set of predefined qualities that an HTML element (or tag) can posses. • Similar to a class attribute but they have already been specified by CSS.
Psuedo-classes • :link – links not yet visited • :visited – previously visited links • :hover – elements pointed at (by a mouse) • :active – elements that are “Activated” such as “active links” • the only other psuedo-classes are :first-child, :focus, :lang()but we wont worry about what they do just yet.
Pseudo-class example • a:link {color: cyan;} • a:visited {color: black;} • a:hover {color: orange;}
Length Units • {margin-right: 24px } • The number can be an integer or a decimal fraction, and can be preceded by + or -. • Units can be absolute or relative: • Absolute: mm, cm, in, pt, pc (millimeters, centimeters, inches, points, picas) • Relative: em, ex, px (the element's font height, the element's x-height, pixels)
Can you have more than one type of style sheet for a website? • YES!
Inheritance – “Cascading” • You can have many levels of style • Web pages often have inline styles at the same time as embedded and linked style sheets. • What if all three define a body {background: color}?
Inheritance- “Cascading” • If there is a conflict then it is resolved in the following priority order: • Inline • Internal/embedded • External/linked • Browser default • So, an Inline style will override a linked style sheet. • Note how the close the style is to the content, the higher the priority.
Descendant Selectors • Concept of inheritance • The closest to the tags is the “youngest” and is the one the browser will use: Here <h2> is a descendant of the <div> element Ex: <div id=“header”> <h3 class=“sub_header”> </h3> </div>