CSS does the width include the padding? – Stack Overflow

When you use percents on the margin/padding then it is relative to it’s OWN WIDTH only. Not height. Not even if you do margin-top:100%. The computed value will be 100% of it’s width.

For exmaple, if you did margin-top:50%; and the width on the element was 800px, it would move it down 400px

참고 사항 (height 에 percentage 값으로 지정하는 경우)

height:100% implies the element is going to have the 100% height of its parent container.

height:auto means, the element will have flexible height i.e. its height will depend upon the height of children elements of it

It is a wildcard, this means it will select all elements within that portion of the DOM.

For example, if I want apply margin to every element on my entire page you can use:

* {
    margin: 10px;
}

You can also use this within sub-selections, for example the following would add a margin to all elements within a paragraph tag:

p * {
    margin: 10px;
}

Your example is doing some css trickery to apply consecutive borders and margins to elements to give them multiple coloured borders. For example, a white border surrounded by a black border.


http://searchbusinessanalytics.techtarget.com/definition/Google-Analytics
 에서 참조

Google Analytics is a free Web analytics service that provides statistics and basic analytical tools for search engine optimization (SEO) and marketing purposes. The service is available to anyone with a Google account. Google bought Urchin Software Corporation in April 2005 and used that company’s Urchin on Demand product as the basis for its current service.

Google Analytics features include:

• Data visualization tools including a dashboardscorecards and motion charts, which display changes in data over time.

• Segmentation for analysis of subsets, such as conversions.

• Custom reports.

• Email-based sharing and communication.

• Integration with other Google products, such as AdWords, Public Data Explorer and Website Optimizer.

Google Analytics is geared toward small and medium-sized retail websites. The service has limitations that make it less suited to more complex websites and larger enterprises. For example, the system collects data through a JavaScript page taginserted in the code of pages the user wants to collect data on. The page tag functions as a Web bug to gather visitor information. However, because it’s reliant oncookies, the system can’t collect data for users who have disabled them. Google also uses sampling in its reports rather than analyzing all available data. 

Furthermore, some security experts have raised concerns about privacy issues in Google Analytics. Through the Google Analytics Dashboard, users can collect information on people whose websites link to social networking sites such asFacebook and Twitter

There are a number of commercial products for enterprises that require more advanced Web analytics, including those from Omniture, Webtrends, IBM’s Cognos product line and Oracle WebCenter.

Summary

The CSS ::after pseudo-element matches a virtual last child of the selected element. Typically used to add cosmetic content to an element, by using thecontent CSS property. This element is inline by default.

Syntax

element:after  { style properties }  /* CSS2 syntax */

element::after { style properties }  /* CSS3 syntax */

The ::after notation was introduced in CSS 3 in order to establish a discrimination between pseudo-classes and pseudo-elements. Browsers also accept the notation :after introduced in CSS 2.

Examples

Simple usage

Let’s create two classes, one for boring paragraphs and one for exciting ones. We can then mark each paragraph by adding a psuedo element to the end of it.

<p class="boring-text">Here is some good old boring text.</p>
<p>Here is some moderate text that is not either boring or exciting.</p>
<p class="exciting-text">Contributing to MDN is easy and fun.
Just hit the edit button to add new live samples, or improve existing samples.</p>
.exciting-text::after {
   content:    "<- now this *is* exciting!"; 
   color:      green;
}

.boring-text::after {
   content:    "<- BORING!";
   color:      red;
}

Sample Example 2

.ribbon{
    position:relative;
    width:50px;
    height:50px;
    background-color: #3BA8E7;
}
.ribbon:after{
    position:absolute;
    content: " ";
    width:50px;
    height:50px;
    top:20%;
    left:50%;
    background-color: #1578B1;
}

Live Sample http://jsfiddle.net/Tripad/fbQTr/3/

Tooltips

The following example shows the use of the ::after pseudo-element in conjunction with the attr() CSS expression and a data-descr custom data attribute to create a pure-CSS, glossary-like tooltip. Checkout the live preview below, or you can see this example in a separate page.

<p>Here is the live example of the above code.<br />
  We have some <span data-descr="collection of words and punctuation">text</span> here with a few
  <span data-descr="small popups which also hide again">tooltips</span>.<br />
  Dont be shy, hove over to take a <span data-descr="not to be taken literally">look</span>.
</p>
    span[data-descr] {
        position: relative;
        text-decoration: underline;
        color: #00F;
        cursor: help;
    }

    span[data-descr]:hover::after {
        content: attr(data-descr);
        position: absolute;
        left: 0;
        top: 24px;
        min-width: 200px;
        border: 1px #aaaaaa solid;
        border-radius: 10px;
        background-color: #ffffcc;
        padding: 12px;
        color: #000000;
        font-size: 14px;
        z-index: 1;
    }