FAG四列圆锥滚子轴承安装说明.pdf

DZone, INCLUDE:Element SelectorsID SelectorsDescendent Selectors Attribute bining Selectors Hot Tips and more...Just in case you’ve not read Core CSS: Part I, I’ll briefly review the purpose of a CSS selector. A selector in a style sheet signals the browser to find matches within those markup (HTML, XHTML, XML) documents to which the style sheet is are more than a few selectors available for use (Table 1), but even intermediate and advanced CSS authors don’t always have an opportunity to use some of them, largely due to cross-browser support issues for a given selector. Core CSS: Part II will cover CSS selectors. Where a selector is unavailable in contemporary Web browsers, a caution will be provided to alert you to any support assist in visualizing how these selectors actually match, for each example you’ll see an element, the corresponding CSS, and a document tree that visualizes what is selected within a sample document. Also provided are some use SelectorsElement selectors, also referred to as “type” selectors, select by matching elements. They are very broad in scope. For example, if I have a million documents with many more millions of h2elements within them, by using an element selector I can single handedly apply styles to all of thoseh2 elements using one rule. Element selectors are supported in all CSS browsers and are very widely used for these ’s a CSS rule using an element selector:h2 {color: #f00; font-family: Garamond; font-size: 22px; font-variant: small-caps;}In the corresponding markup document(s), all h2s are selected and the style is applied (Figure 1).Element Selectors, continuedClass SelectorsClass selectors are extremely useful selectors that allow authors to add a class attribute to a given element in the markup, with a custom value. Then using that value preceded by a dot, write a corresponding rule using the class name. An example of an element with an added class attri