Wednesday 28th of September 2016 05:38:32 AM

CSS Style Guide

 

This Style Guide explains the markup and design requirements for web projects, along with various standards and best practices.

projects authored in valid XHTML 1.0 Transitional and styled with valid Cascading Style Sheets will be described here. See the XHTML and CSS sections below for details. Additional sections of this Style Guide, coming soon, will provide information on writing for the web, naming and filing your documents, and other useful topics and guidelines.

XHTML: Guidelines & Benefits

Library projects must be authored in structural XHTML 1.0 Transitional. Page authors should follow accessibility guidelines in compliance with U.S. Law, and so that our site’s content will be made available to the widest possible number of people, browsers, and Internet devices. In addition, all XHTML must validate.

XHTML Guidelines
The rules of XHTML as compared to HTML—an easy transition
What is XML?
A brief introduction to the foundation of XHTML
XHTML Benefits
Four key benefits of converting from HTML to XHTML
XHTML Authoring Tips & Tools
Simplifying the work process—includes tips on thinking structurally, and tools for hand-coders and Dreamweaver users
XHTML Accessibility Tips
Making sure your pages can be read by all visitors, browsers, and devices
XHTML Validation
Ensuring interoperability by avoiding errors and sticking to standards

CSS: Style Sheets & Tips

Library projects must use valid Cascading Style Sheets (CSS) to control typography, color, and other layout elements. Style Sheets must be linked in a way that accommodates the capabilities of new and old browsers.

CSS Guidelines
Tips on authoring and linking to Style Sheets
Steal These Style Sheets!
Style Sheets for your use in Library projects
CSS Validation
Ensuring that your Style Sheets are error-free (same as XHTML validation)

A number of valid Style Sheets have been provided for your use. If you wish to create your own Style Sheets, please discuss your requirements with the Branch Library’s Web Coordinator.

link popularity
dashed lines are for illustrative purposes only.) As Figure 7-7 demonstrates, 10 pixels of space are added to each side of the content area. This is somewhat similar to using the HSPACE and VSPACE attributes in HTML. In fact, you can use margin to set extra space around an image. Let's say you want 1 em of space surrounding all images:

That's all it takes.

There may be times where you want a different amount of space on each side of an element. That's simple as well. If we want all The 2nd category of Java applications called Java Application Servers (or app servers) and they make good use of XML. Unlike client side graphical Java apps (from the previous section) which are very standalone in their operations, app servers tie many different networked software components together in order to provide information from multiple sources to a set of client side Java apps or web browsers (maybe even running on different devices). This is shown in Figure 2. An app server is actually a conglomeration of several distributed and client/server software systems. So when you write an app server, you are actually writing many different software systems which are all networked to work together, to process information that comes from various sources, and distribute this information to a set of client apps (that you also have to write) running on different devices and platforms.

How can XML help app servers do their work? As you can see in Figure 2, in order for the app server to harvest information from such a rich variety of sources, there must be some common ground between all of these sources (each of which might be running on a different hardware and software system). This common ground is the information which flows throughout the entire system, regardless of what source the information comes from. CORBA is an example of tying disparate systems together based on the interfaces that certain remote objects implement. XML does the same thing for data. It allows these disparate systems to share information in a medium that consists only of pure information (and the structural relationships that exist inside of that information). By taking the lowest common denominator approach by using plain text to encode data, XML allows these systems to talk with each other without requiring any special binary information format converters or other service layers to translate between binary formats (for encoding data). Also, since HTTP already supports transmission of plain text, it is completely natural to move XML around using the Hyper Text Transfer Protocol through firewalls and disparate networks. This is shown in Figure 3. XML can be transmitted between systems using one of the most prevalent protocols in use today, Hypertext Transfer Protocol or HTTP 1.1 (which is the protocol of the web).

App server developers are not restricted to using HTTP, they can transmit and recieve XML information using simple remote CORBA objects and RMI objects. The key is that by using XML, it makes these remote services or objects easier to build. And, by sticking with XML, any one of these technologies can be used in your design of your app server. You can use whatever technology is most appropriate to getting the job done, knowing that all the information flows as XML and can be processed by any part of the system. The reason Java object serialization did not achieve this is because it encodes object data to a binary format that is dependent on too many things (like the JVM version, and the existence of classes when things are deserialized, etc). XML is not limited by any of these restrictions (or problems), which makes it much easier to create systems that allow XML information to flow between different subsystems. Also by relying only on the data, large portions of the system can be replaced with better or different implementations for future-readiness.

App servers traditionally give their client apps access to information in remote databases, remote file systems, remote object repositories, remote web resources, and even other app servers. All these information sources don't even need to reside on the machine that hosts the app server. These remote resources may be on other machines on the Intranet or the Internet. Using Java and XML, RMI, JDBC, CORBA, JNDI, Servlet and Swing, you can create app servers that can integrate all kinds of remote and local information resources, and client apps that allow you to remotely or locally access this information from the app server.

effects. This example is shown in Figure 6-18:

P {color: black;}H1 {color: white; background-color: rgb(20%,20%,20%);}
Figure 6-18

Figure 6-18. A nifty effect for H1 elements

This shows but one example of how displays can be dramaticallychanged with just a few styles. Of course, there are as manycombinations as there are colors, but we can't exactly showthem here -- being stuck in grayscale as we are -- however,we'll try to give you some idea of what you can do. Here are a

XML is language independent

By being language independent, XML bypasses the requirement to have a standard binary encoding or storage format. Language independence also fosters immense interoperability amongst heterogeneous systems. It is also good for future compatilbilty. For example, if in the future a product needs to be changed in order to deal with a new computing paradigm or network protocol, by keeping XML flowing through the system, addition of a new layer to deal with this change is feasible.

DOM and SAX are open, language-independent set of interfaces

By defining a set of programming language independent interfaces that allow the accessing and mutation of XML documents, the W3C made it easier for programmers to deal with XML. Not only does XML address the need for a standard information encoding and storage format, it also allows programmers a standard way to use that information. SAX is a very low level API, but it is more than what has been available before it. DOM is a higher level API that even provides a default object model for all XML documents (saving time in creating one from scratch if you are using data is document data).

Without a value for line-height, it wouldn't be possible to perform percentage-value vertical alignments. The height of the image itself has no relevance when it comes to vertical alignment: the value of line-height is all that matters.

8.4.4.1. Adding box properties

After everything else, applying uses numbers, is discussed later in this section.

Perhaps you want your H1 elements to be colored ashade of red somewhere between the values for red and maroon.red is simply rgb(100%,0%,0%),whereas maroon is more like(50%,0%,0%). In order to get a color between thosetwo, you might try this:

H1 {color: rgb(75%,0%,0%);}