HTML tags were originally designed to define the content of a document. They were supposed to say "This is a header", "Th...
HTML tags were originally designed to define the content of a
document. They were supposed to say "This is a header", "This is a
paragraph", "This is a table", by using tags like <h1>, <p>,
<table>, and so on. The layout of the document was supposed to be
taken care of by the browser, without using any formatting tags.
As the two major browsers - Netscape and Internet Explorer - continued
to add new HTML tags and attributes (like the <font> tag and the
color attribute) to the original HTML specification, it became more and
more difficult to create Web sites where the content of HTML documents
was clearly separated from the document's presentation layout.
To solve this problem, the World Wide Web Consortium (W3C) - the non
profit, standard setting consortium, responsible for standardizing HTML -
created STYLES in addition to HTML 4.0.
All major browsers support Cascading Style Sheets.
Style Sheets Can Save a Lot of Work
Styles sheets define HOW HTML elements are to be displayed, just like
the font tag and the color attribute in HTML 3.2. Styles are normally
saved in external .css files. External style sheets enable you to
change the appearance and layout of all the pages in your Web, just by
editing one single CSS document!
CSS is a breakthrough in Web design because it allows developers to
control the style and layout of multiple Web pages all at once. As a Web
developer you can define a style for each HTML element and apply it to
as many Web pages as you want. To make a global change, simply change
the style, and all elements in the Web are updated automatically.
Browser support: IE: Internet Explorer, M: Mac IE only, F: Firefox, N: Netscape.W3C: The number in the "W3C" column indicates in which CSS recommendation the property is defined (CSS1 or CSS2).
Background
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| background | A shorthand property for setting all background properties in one declaration | background-color background-image background-repeat background-attachment background-position | 4 | 1 | 6 | 1 |
| background-attachment | Sets whether a background image is fixed or scrolls with the rest of the page | scroll fixed | 4 | 1 | 6 | 1 |
| background-color | Sets the background color of an element | color-rgb color-hex color-name transparent | 4 | 1 | 4 | 1 |
| background-image | Sets an image as the background | url(URL) none | 4 | 1 | 4 | 1 |
| background-position | Sets the starting position of a background image | top left top center top right center left center center center right bottom left bottom center bottom right x% y% xpos ypos | 4 | 1 | 6 | 1 |
| background-repeat | Sets if/how a background image will be repeated | repeat repeat-x repeat-y no-repeat | 4 | 1 | 4 | 1 |
Border
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| border | A shorthand property for setting all of the properties for the four borders in one declaration | border-width border-style border-color | 4 | 1 | 4 | 1 |
| border-bottom | A shorthand property for setting all of the properties for the bottom border in one declaration | border-bottom-width border-style border-color | 4 | 1 | 6 | 1 |
| border-bottom-color | Sets the color of the bottom border | border-color | 4 | 1 | 6 | 2 |
| border-bottom-style | Sets the style of the bottom border | border-style | 4 | 1 | 6 | 2 |
| border-bottom-width | Sets the width of the bottom border | thin medium thick length | 4 | 1 | 4 | 1 |
| border-color | Sets the color of the four borders, can have from one to four colors | color | 4 | 1 | 6 | 1 |
| border-left | A shorthand property for setting all of the properties for the left border in one declaration | border-left-width border-style border-color | 4 | 1 | 6 | 1 |
| border-left-color | Sets the color of the left border | border-color | 4 | 1 | 6 | 2 |
| border-left-style | Sets the style of the left border | border-style | 4 | 1 | 6 | 2 |
| border-left-width | Sets the width of the left border | thin medium thick length | 4 | 1 | 4 | 1 |
| border-right | A shorthand property for setting all of the properties for the right border in one declaration | border-right-width border-style border-color | 4 | 1 | 6 | 1 |
| border-right-color | Sets the color of the right border | border-color | 4 | 1 | 6 | 2 |
| border-right-style | Sets the style of the right border | border-style | 4 | 1 | 6 | 2 |
| border-right-width | Sets the width of the right border | thin medium thick length | 4 | 1 | 4 | 1 |
| border-style | Sets the style of the four borders, can have from one to four styles | none hidden dotted dashed solid double groove ridge inset outset | 4 | 1 | 6 | 1 |
| border-top | A shorthand property for setting all of the properties for the top border in one declaration | border-top-width border-style border-color | 4 | 1 | 6 | 1 |
| border-top-color | Sets the color of the top border | border-color | 4 | 1 | 6 | 2 |
| border-top-style | Sets the style of the top border | border-style | 4 | 1 | 6 | 2 |
| border-top-width | Sets the width of the top border | thin medium thick length | 4 | 1 | 4 | 1 |
| border-width | A shorthand property for setting the width of the four borders in one declaration, can have from one to four values | thin medium thick length | 4 | 1 | 4 | 1 |
Classification
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| clear | Sets the sides of an element where other floating elements are not allowed | left right both none | 4 | 1 | 4 | 1 |
| cursor | Specifies the type of cursor to be displayed | url auto crosshair default pointer move e-resize ne-resize nw-resize n-resize se-resize sw-resize s-resize w-resize text wait help | 4 | 1 | 6 | 2 |
| display | Sets how/if an element is displayed | none inline block list-item run-in compact marker table inline-table table-row-group table-header-group table-footer-group table-row table-column-group table-column table-cell table-caption | 4 | 1 | 4 | 1 |
| float | Sets where an image or a text will appear in another element | left right none | 4 | 1 | 4 | 1 |
| position | Places an element in a static, relative, absolute or fixed position | static relative absolute fixed | 4 | 1 | 4 | 2 |
| visibility | Sets if an element should be visible or invisible | visible hidden collapse | 4 | 1 | 6 | 2 |
Dimension
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| height | Sets the height of an element | auto length % | 4 | 1 | 6 | 1 |
| line-height | Sets the distance between lines | normal number length % | 4 | 1 | 4 | 1 |
| max-height | Sets the maximum height of an element | none length % | - | 1 | 6 | 2 |
| max-width | Sets the maximum width of an element | none length % | - | 1 | 6 | 2 |
| min-height | Sets the minimum height of an element | length % | - | 1 | 6 | 2 |
| min-width | Sets the minimum width of an element | length % | - | 1 | 6 | 2 |
| width | Sets the width of an element | auto % length | 4 | 1 | 4 | 1 |
Font
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| font | A shorthand property for setting all of the properties for a font in one declaration | font-style font-variant font-weight font-size/line-height font-family caption icon menu message-box small-caption status-bar | 4 | 1 | 4 | 1 |
| font-family | A prioritized list of font family names and/or generic family names for an element | family-name generic-family | 3 | 1 | 4 | 1 |
| font-size | Sets the size of a font | xx-small x-small small medium large x-large xx-large smaller larger length % | 3 | 1 | 4 | 1 |
| font-size-adjust | Specifies an aspect value for an element that will preserve the x-height of the first-choice font | none number | - | 1 | - | 2 |
| font-stretch | Condenses or expands the current font-family | normal wider narrower ultra-condensed extra-condensed condensed semi-condensed semi-expanded expanded extra-expanded ultra-expanded | - | - | - | 2 |
| font-style | Sets the style of the font | normal italic oblique | 4 | 1 | 4 | 1 |
| font-variant | Displays text in a small-caps font or a normal font | normal small-caps | 4 | 1 | 6 | 1 |
| font-weight | Sets the weight of a font | normal bold bolder lighter 100 200 300 400 500 600 700 800 900 | 4 | 1 | 4 | 1 |
Generated Content
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| content | Generates content in a document. Used with the :before and :after pseudo-elements | string url counter(name) counter(name, list-style-type) counters(name, string) counters(name, string, list-style-type) attr(X) open-quote close-quote no-open-quote no-close-quote | 1 | 6 | 2 | |
| counter-increment | Sets how much the counter increments on each occurrence of a selector | none identifier number | 2 | |||
| counter-reset | Sets the value the counter is set to on each occurrence of a selector | none identifier number | 2 | |||
| quotes | Sets the type of quotation marks | none string string | - | 1 | 6 | 2 |
List and Marker
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| list-style | A shorthand property for setting all of the properties for a list in one declaration | list-style-type list-style-position list-style-image | 4 | 1 | 6 | 1 |
| list-style-image | Sets an image as the list-item marker | none url | 4 | 1 | 6 | 1 |
| list-style-position | Sets where the list-item marker is placed in the list | inside outside | 4 | 1 | 6 | 1 |
| list-style-type | Sets the type of the list-item marker | none disc circle square decimal decimal-leading-zero lower-roman upper-roman lower-alpha upper-alpha lower-greek lower-latin upper-latin hebrew armenian georgian cjk-ideographic hiragana katakana hiragana-iroha katakana-iroha | 4 | 1 | 4 | 1 |
| marker-offset | auto length | 1 | 7 | 2 |
Margin
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| margin | A shorthand property for setting the margin properties in one declaration | margin-top margin-right margin-bottom margin-left | 4 | 1 | 4 | 1 |
| margin-bottom | Sets the bottom margin of an element | auto length % | 4 | 1 | 4 | 1 |
| margin-left | Sets the left margin of an element | auto length % | 3 | 1 | 4 | 1 |
| margin-right | Sets the right margin of an element | auto length % | 3 | 1 | 4 | 1 |
| margin-top | Sets the top margin of an element | auto length % | 3 | 1 | 4 | 1 |
Outlines
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| outline | A shorthand property for setting all the outline properties in one declaration | outline-color outline-style outline-width | - | 1.5 | - | 2 |
| outline-color | Sets the color of the outline around an element | color invert | - | 1.5 | - | 2 |
| outline-style | Sets the style of the outline around an element | none dotted dashed solid double groove ridge inset outset | - | 1.5 | - | 2 |
| outline-width | Sets the width of the outline around an element | thin medium thick length | - | 1.5 | - | 2 |
Padding
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| padding | A shorthand property for setting all of the padding properties in one declaration | padding-top padding-right padding-bottom padding-left | 4 | 1 | 4 | 1 |
| padding-bottom | Sets the bottom padding of an element | length % | 4 | 1 | 4 | 1 |
| padding-left | Sets the left padding of an element | length % | 4 | 1 | 4 | 1 |
| padding-right | Sets the right padding of an element | length % | 4 | 1 | 4 | 1 |
| padding-top | Sets the top padding of an element | length % | 4 | 1 | 4 | 1 |
Positioning
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| bottom | Sets how far the bottom edge of an element is above/below the bottom edge of the parent element | auto % length | 5 | 1 | 6 | 2 |
| clip | Sets the shape of an element. The element is clipped into this shape, and displayed | shape auto | 4 | 1 | 6 | 2 |
| left | Sets how far the left edge of an element is to the right/left of the left edge of the parent element | auto % length | 4 | 1 | 4 | 2 |
| overflow | Sets what happens if the content of an element overflow its area | visible hidden scroll auto | 4 | 1 | 6 | 2 |
| position | Places an element in a static, relative, absolute or fixed position | static relative absolute fixed | 4 | 1 | 4 | 2 |
| right | Sets how far the right edge of an element is to the left/right of the right edge of the parent element | auto % length | 5 | 1 | 6 | 2 |
| top | Sets how far the top edge of an element is above/below the top edge of the parent element | auto % length | 4 | 1 | 4 | 2 |
| vertical-align | Sets the vertical alignment of an element | baseline sub super top text-top middle bottom text-bottom length % | 4 | 1 | 4 | 1 |
| z-index | Sets the stack order of an element | auto number | 4 | 1 | 6 | 2 |
Table
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| border-collapse | Sets whether the table borders are collapsed into a single border or detached as in standard HTML | collapse separate | 5 | 1 | 7 | 2 |
| border-spacing | Sets the distance that separates cell borders (only for the "separated borders" model) | length length | 5M | 1 | 6 | 2 |
| caption-side | Sets the position of the table caption | top bottom left right | 5M | 1 | 6 | 2 |
| empty-cells | Sets whether or not to show empty cells in a table (only for the "separated borders" model) | show hide | 5M | 1 | 6 | 2 |
| table-layout | Sets the algorithm used to display the table cells, rows, and columns | auto fixed | 5 | 1 | 6 | 2 |
Text
| Property | Description | Values | IE | F | N | W3C |
|---|---|---|---|---|---|---|
| color | Sets the color of a text | color | 3 | 1 | 4 | 1 |
| direction | Sets the text direction | ltr rtl | 6 | 1 | 6 | 2 |
| line-height | Sets the distance between lines | normal number length % | 4 | 1 | 4 | 1 |
| letter-spacing | Increase or decrease the space between characters | normal length | 4 | 1 | 6 | 1 |
| text-align | Aligns the text in an element | left right center justify | 4 | 1 | 4 | 1 |
| text-decoration | Adds decoration to text | none underline overline line-through blink | 4 | 1 | 4 | 1 |
| text-indent | Indents the first line of text in an element | length % | 4 | 1 | 4 | 1 |
| text-shadow | none color length | |||||
| text-transform | Controls the letters in an element | none capitalize uppercase lowercase | 4 | 1 | 4 | 1 |
| unicode-bidi | normal embed bidi-override | 5 | 2 | |||
| white-space | Sets how white space inside an element is handled | normal pre nowrap | 5 | 1 | 4 | 1 |
| word-spacing | Increase or decrease the space between words | normal length | 6 | 1 | 6 | 1 |
Pseudo-classes
| Pseudo-class | Purpose | IE | F | N | W3C |
|---|---|---|---|---|---|
| :active | Adds special style to an activated element | 4 | 1 | 8 | 1 |
| :focus | Adds special style to an element while the element has focus | - | 1.5 | 8 | 2 |
| :hover | Adds special style to an element when you mouse over it | 4 | 1 | 7 | 1 |
| :link | Adds special style to an unvisited link | 3 | 1 | 4 | 1 |
| :visited | Adds special style to a visited link | 3 | 1 | 4 | 1 |
| :first-child | Adds special style to an element that is the first child of some other element | - | 1 | 7 | 2 |
| :lang | Allows the author to specify a language to use in a specified element | - | 1 | 8 | 2 |
Pseudo-elements
| Pseudo-element | Purpose | IE | F | N | W3C |
|---|---|---|---|---|---|
| :first-letter | Adds special style to the first letter of a text | 5 | 1 | 8 | 1 |
| :first-line | Adds special style to the first line of a text | 5 | 1 | 8 | 1 |
| :before | Inserts some content before an element | 1.5 | 8 | 2 | |
| :after | Inserts some content after an element | 1.5 | 8 | 2 |
