Cascading Style Sheet Language CSS3

A Basic Introduction

Cascading Style Sheet language CSS3 is a companion language to HTML5. While HTML controls the content of a webpage, an externally linked CSS file controls how the content is displayed.

CSS3 is the latest version of CSS. It is used in companion with HTML5.

Change Background with Cascading Style Sheet Language CSS3

To change the background color of a <body> tag, for example,  the code is:

body { background: blue; }

 

CSS files are typically saved with a name like “styles.css“.

Connect Cascading Style Sheet Language CSS3 to HTML5

 

In order for stylings to be seen on a page, the CSS file must be meta-linked to the HTML file to apply the stylings. The code to link the file should be placed in inside the <head> tags.


<!DOCTYPE html>
<html lang="en">

<head>

<title>Page Title</title>

<link href="css/styles.css" rel="stylesheet">

</head>

<body>

</body>
</html>

 

The above code example creates a meta-link. The href attribute must point to the correct name and path of the CSS file. It is common practice to keep CSS files in a folder named “css“.

One of the key features of CSS3 is that only one file is needed per web application. Once you link that style sheet to all the desired HTML pages, then all those pages will be changed according to the CSS3 commands.

Change Text Color with Cascading Style Sheet Language CSS3

Another simple command is changing the text color of the body.


body {
background: blue;
color: green;
}

 

Sufficient practice with CSS3 commands will allow any designer take control of how content is displayed.

Python Reserved Words to Know

This post is as a reference for Python reserved words.

Python reserved words have special meaning, and must only be used in regard to their special meaning. They include:

and not as
global assert del
while elif or
else from with
if pass break
import class raise
continue return def
lambda yield except
print exec finally
for try in
is

You must not use these words as variables, because they already have a special command meaning for Python.

Python understands these commands like a trained dog understands “sit”. So again, you must not use Python reserved words as variables.

Program with Python Reserved Words

You can use one of these Python reserved words to write your first Python program.

print 'Hello World!'

 

This, of course, is the classic ‘Hello World!’ program, written in Python.

Computer Hardware Architecture Basics

Before learning how to program computers, take a moment to understand the computer hardware architecture basics.

The Central Processing Unit

The CPU can execute commands extremely fast. The catch is, it has to be told what to do, or it won’t do anything.

The Main Memory

The main memory stores information that the CPU can retrieve extremely fast. Anything stored here will vanish when the computer is turned off.

The Secondary Memory

This stores memory but it is very slow. We need it because it can store memory even without power. Examples of this are a hard drive, USB stick, or disk drives.

The Network

The network can serve as remote secondary memory, because information is stored over the network that you can retrieve.

The Input and Output Devices

This could be a mouse, keyboard, monitor, speaker, joystick, etc. You use these to interact with your computer.

Properly Edit HTML5 – How To

To properly edit HTML5, every page of content should be wrapped with the <html> tag and the <body> tag.

This next bit is kind of tricky, but you should also include a <header> tag between your <html> and <body> tag. Within the header you should put a <title> tag. This contains meta-data about your web page, and is an important part of SEO. The title will not display on your page, but it should display on your browser tab. It is common for <title> and <h1> tags to contain the same text.

Below is a picture from a text editor to show you a properly edited basic page.

basic HTML5

HTML5 Makes Your Page Respond To Different Screen Sizes

Visit some random web pages and play with size of your browser window. Alternatively, view the pages on a desktop and then a smart-phone. Does the page respond to different screen sizes? If it does then you can assume that it was edited in HTML5.

Now take a moment to view the source code of the world’s first web page. You can view the source code and the HTML that was written. Using Google Chrome to view source code you click on ‘Tools’ and select ‘Developer Tools’. Notice that the HTML is a bit different from HTML5. That’s because HTML is a living language that constantly evolves. HTML5 simply represents a point when the W3C decided to mark it as the latest standard for HTML editing.

 

Must Know HTML5 Tags

You should become familiar with must know HTML5 tags that appear on almost every page.

If you want to put an image on your page then you will need to use the <img> tag with a src attribute. The source attribute contains the URL for your image.

For an example you can go to Google Images. Be sure to click on ‘Search Tools’ and ‘Labeled for Reuse’ so you do not violate any copyrights. Search for an image you like, right-click on it, and select ‘Save Image URL’.

Example of HTML5 <img> Tag

Here is an example of how to edit your HTML5 tag to display a standard Google image.

<img src=”https://encrypted-tbn2.gstatic.com/imagesq=tbn:ANd9GcSdW68P3DrocDWRhCvvr_SrKUyffhspfjGUqlHo03NbOlEbBi9w” />

 

Note that the image tag is self-contained. It does not have a separate </img> closing tag.

Example of HTML5 <img> Tag with Size Percentage Attribute

Here is an image of some bananas, with the width adjusted to 50%:

<img src=”https://encrypted-tbn3.gstatic.com/imagesq=tbn:ANd9GcTq9pG5b4c2fo2EIV044MAChiwDCYt4ReShWJg0cqwrQGu7xFlNzA” width=”50%” />

 

Notice that you can use a percentage for adjusting the width. This is a nice feature to give your site a responsive quality.

Example of HTML5 <a> Tag Wrapped Over <img> Tag

You can also make the image a link itself. You can do this if you want to direct a user to another URL by clicking on the image.

The following is an example of how to edit your code so the image of bananas links to an article about bananas.

<a href=”http://healthyeating.sfgate.com/health-benefits-one-banana-day-3316.html”>
++++<img src=”https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTq9pG5b4c2fo2EIV044MAChiwDCYt4ReShWJg0cqwrQGu7xFlNzA” width=”50%” />
</a>

 

As you can see, you simply put the <img> tag inside the <a> tag. Wrapping tags inside tags is a common practice with HTML5 editing, and it can go several layers deep. However, it is not permitted to overlap tags.

For example, the series of tags <p> <h2> </p> </h2> is not allowed. You can probably see by now why overlapping tags does not make sense.

Example of Using HTML5 Smaller Header Tag

You can make a smaller heading as follows:

<h3>This is a smaller heading. Use it where you want a small heading.</h3>

 

Example of HTML5 List Tags

You can also creat a numbered list, or as the tag suggests, an ordered list as follows:

<h4>Top Three Rock Guitar Players</h4>
++++<ol>
++++++++<li>Jimi Hendrix</li>
++++++++<li>Jimmy Page</li>
++++++++<li>Eddie Van Halen</li>
++++</ol>

 

You can also do an un-ordered list that shows bullet points.

<h4>Random Prime Numbers</h4>
++++<ul>
++++++++<li>1973</li>
++++++++<li>677</li>
++++++++<li>3</li>
++++</ul>

 

Lists can add a nice dynamic to your page content. You can practice making lists at this free and interactive HTML Lists Tutorial at W3 Schools.

 

There are no universal rules on how to use indentations, but you should try to edit it so that it’s easy to read. Your eyes will thank you later. Writing clean code could also help you land a job.