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diff --git a/css.html.markdown b/css.html.markdown index d8f30ca3..8ee4f4b9 100644 --- a/css.html.markdown +++ b/css.html.markdown @@ -6,20 +6,21 @@ contributors: - ["Geoffrey Liu", "https://github.com/g-liu"] - ["Connor Shea", "https://github.com/connorshea"] - ["Deepanshu Utkarsh", "https://github.com/duci9y"] + - ["Tyler Mumford", "https://tylermumford.com"] filename: learncss.css --- -In the early days of the web there were no visual elements, just pure text. But with further development of web browsers, fully visual web pages also became common. +Web pages are built with HTML, which specifies the content of a page. CSS (Cascading Style Sheets) is a separate language which specifies a page's **appearance**. -CSS helps maintain separation between the content (HTML) and the look-and-feel of a web page. +CSS code is made of static *rules*. Each rule takes one or more *selectors* and gives specific *values* to a number of visual *properties*. Those properties are then applied to the page elements indicated by the selectors. -CSS lets you target different elements on an HTML page and assign different visual properties to them. +This guide has been written with CSS 2 in mind, which is extended by the new features of CSS 3. -This guide has been written for CSS 2, though CSS 3 is fast becoming popular. - -**NOTE:** Because CSS produces visual results, in order to learn it, you need try everything in a CSS playground like [dabblet](http://dabblet.com/). +**NOTE:** Because CSS produces visual results, in order to learn it, you need to try everything in a CSS playground like [dabblet](http://dabblet.com/). The main focus of this article is on the syntax and some general tips. +## Syntax + ```css /* comments appear inside slash-asterisk, just like this line! there are no "one-line comments"; this is the only comment style */ @@ -28,7 +29,7 @@ The main focus of this article is on the syntax and some general tips. ## SELECTORS #################### */ -/* the selector is used to target an element on a page. +/* the selector is used to target an element on a page. */ selector { property: value; /* more properties...*/ } /* @@ -69,7 +70,7 @@ div { } [otherAttr|='en'] { font-size:smaller; } -/* You can concatenate different selectors to create a narrower selector. Don't +/* You can combine different selectors to create a more focused selector. Don't put spaces between them. */ div.some-class[attr$='ue'] { } @@ -92,7 +93,7 @@ div.some-parent.class-name { } .i-am-any-element-before ~ .this-element { } /* There are some selectors called pseudo classes that can be used to select an - element when it is in a particular state */ + element only when it is in a particular state */ /* for example, when the cursor hovers over an element */ selector:hover { } @@ -103,7 +104,7 @@ selector:visited { } /* or hasn't been visited */ selected:link { } -/* or an element in focus */ +/* or an element is in focus */ selected:focus { } /* any element that is the first child of its parent */ @@ -156,10 +157,10 @@ selector { color: tomato; /* a named color */ color: rgb(255, 255, 255); /* as rgb values */ color: rgb(10%, 20%, 50%); /* as rgb percentages */ - color: rgba(255, 0, 0, 0.3); /* as rgba values (CSS 3) Note: 0 < a < 1 */ + color: rgba(255, 0, 0, 0.3); /* as rgba values (CSS 3) Note: 0 <= a <= 1 */ color: transparent; /* equivalent to setting the alpha to 0 */ color: hsl(0, 100%, 50%); /* as hsl percentages (CSS 3) */ - color: hsla(0, 100%, 50%, 0.3); /* as hsla percentages with alpha */ + color: hsla(0, 100%, 50%, 0.3); /* as hsl percentages with alpha */ /* Images as backgrounds of elements */ background-image: url(/img-path/img.jpg); /* quotes inside url() optional */ @@ -194,7 +195,7 @@ Save a CSS stylesheet with the extension `.css`. ## Precedence or Cascade -An element may be targeted by multiple selectors and may have a property set on it in more than once. In these cases, one of the rules takes precedence over others. Generally, a rule in a more specific selector take precedence over a less specific one, and a rule occuring later in the stylesheet overwrites a previous one. +An element may be targeted by multiple selectors and may have a property set on it in more than once. In these cases, one of the rules takes precedence over others. Rules with a more specific selector take precedence over a less specific one, and a rule occuring later in the stylesheet overwrites a previous one. This process is called cascading, hence the name Cascading Style Sheets. @@ -238,10 +239,10 @@ Most of the features in CSS 2 (and many in CSS 3) are available across all brows ## Resources -* To run a quick compatibility check, [CanIUse](http://caniuse.com). -* CSS Playground [Dabblet](http://dabblet.com/). -* [Mozilla Developer Network's CSS documentation](https://developer.mozilla.org/en-US/docs/Web/CSS) -* [Codrops' CSS Reference](http://tympanus.net/codrops/css_reference/) +* [CanIUse](http://caniuse.com) (Detailed compatibility info) +* [Dabblet](http://dabblet.com/) (CSS playground) +* [Mozilla Developer Network's CSS documentation](https://developer.mozilla.org/en-US/docs/Web/CSS) (Tutorials and reference) +* [Codrops' CSS Reference](http://tympanus.net/codrops/css_reference/) (Reference) ## Further Reading |