-last edited on (24th Apr 2022).Welcome to my page . . .
Cascading Style Sheets, fondly referred to as CSS, is a simple design language intended to simplify the process of making web pages presentable. CSS handles the look and feel part of a web page. Using CSS, you can control the color of the text, the style of fonts, the spacing between paragraphs, how columns are sized and laid out, what background images or colors are used, layout designs,variations in display for different devices and screen sizes as well as a variety of other effects. CSS is easy to learn and understand but it provides powerful control over the presentation of an HTML document. Most commonly, CSS is combined with the markup languages HTML or XHTML.
CSS is created and maintained through a group of people within the W3C called the CSS Working Group. The CSS Working Group creates documents called specifications. When a specification has been discussed and officially ratified by the W3C members, it becomes a recommendation. These ratified specifications are called recommendations because the W3C has no control over the actual implementation of the language. Independent companies and organizations create that software. NOTE − The World Wide Web Consortium, or W3C is a group that makes recommendations about how the Internet works and how it should evolve.
Cascading Style Sheets level 1 (CSS1) came out of W3C as a recommendation in December 1996. This version describes the CSS language as well as a simple visual formatting model for all the HTML tags. CSS2 became a W3C recommendation in May 1998 and builds on CSS1. This version adds support for media-specific style sheets e.g. printers and aural devices, downloadable fonts, element positioning and tables.
Cascading Style Sheets, fondly referred to as CSS, is a simple design language intended to simplify the process of making web pages presentable.
CSS handles the look and feel part of a web page. Using CSS, you can control the color of the text, the style of fonts, the spacing between paragraphs, how columns are sized and laid out, what background images or colors are used, layout designs,variations in display for different devices and screen sizes as well as a variety of other effects.
CSS is easy to learn and understand but it provides powerful control over the presentation of an HTML document. Most commonly, CSS is combined with the markup languages HTML or XHTML.
As mentioned before, CSS is one of the most widely used style language over the web. I'm going to list few of them here:
CSS saves time - You can write CSS once and then reuse same sheet in multiple HTML pages. You can define a style for each HTML element and apply it to as many Web pages as you want.
Pages load faster - If you are using CSS, you do not need to write HTML tag attributes every time. Just write one CSS rule of a tag and apply it to all the occurrences of that tag. So less code means faster download times.
Easy maintenance - To make a global change, simply change the style, and all elements in all the web pages will be updated automatically.
Superior styles to HTML - CSS has a much wider array of attributes than HTML, so you can give a far better look to your HTML page in comparison to HTML attributes.
Multiple Device Compatibility - Style sheets allow content to be optimized for more than one type of device. By using the same HTML document, different versions of a website can be presented for handheld devices such as PDAs and cell phones or for printing.
Global web standards - Now HTML attributes are being deprecated and it is being recommended to use CSS. So its a good idea to start using CSS in all the HTML pages to make them compatible to future browsers.
class Selector :
This selector is used to make or give a style for a unified class.In simple terms it helps us to style all those elements of html tags which uses the same class. For example you dont need to give to give different styles to ever element of the html element rather declare an atribute with class="a1" now where ever the a1 is marked with what ever element hence it will be styled in a unified way. To start to style we need preFIX it with a period operator (.)
.a1{
background-color:red;
}
Universal Selector :
Rather than selecting elements of a specific type, the universal selector quite simply matches the name of any element type. It styles all the elements of the document
* {
color: #000000;
}
The Descendant Selectors:
Suppose you want to apply a style rule to a particular element only when it lies inside a particular element. As given in the following example, style rule will apply to <em> element only when it lies inside <ul> tag.
ul em {
color: #000000;
}
The ID Selectors :
You can define style rules based on the id attribute of the elements. All the elements having that id will be formatted according to the defined rule.
#black {
color: #000000;
}
This rule renders the content in black for every element with id attribute set tb black in our document. You can make it a bit more particular. For example −
h1#black {
color: #000000;
}
The true power of id selectors is when they are used as the foundation for descendant selectors, For example −
#black h2 {
color: #000000;
}
In this example all level 2 headings will be displayed in black color when those headings will lie with in tags having id attribute set to black.
The Attribute Selectors :
You can also apply styles to HTML elements with particular attributes. The style rule below will match all the input elements having a type attribute with a value of text −
input[type = "text"] {
color: #000000;
}
The advantage to this method is that the <input type = "submit" /> element is unaffected, and the color applied only to the desired text fields.
There are following rules applied to attribute selector.
p[lang] − Selects all paragraph elements with a lang attribute.
p[lang="fr"] − Selects all paragraph elements whose lang attribute has a value of exactly "fr".
p[lang~="fr"] − Selects all paragraph elements whose lang attribute contains the word "fr".
p[lang|="en"] − Selects all paragraph elements whose lang attribute contains values that are exactly "en", or begin with "en-".
Embedded systems :
CSS pseudo-classes are used to add special effects to some selectors. You do not need to use JavaScript or any other script to use those effects. A simple syntax of pseudo-classes is as follow
selector:pseudo-class {property: value}
for example
CSS classes can also be used with pseudo-classes −
selector.class:pseudo-class {property: value}
1. :link
Use this class to add special style to an unvisited link.
2. :visited
Use this class to add special style to a visited link.
3. :hover
Use this class to add special style to an element when you mouse over it.
4. :active
Use this class to add special style to an active element.
5. :focus
Use this class to add special style to an element while the element has focus.
6. :first-child
Use this class to add special style to an element that is the first child of some other element.
7. :lang
Use this class to specify a language to use in a specified element
These are certain properties of css :
scroll inside the box to explore more properties. . .
CSS animations −
The CSS3 animations take it a step further with keyframe-based animations that allow you to specify the changes in CSS properties over time as a set of keyframes, like flash animations. Creating CSS animations is a two step process, as shown in the example below:
The first step of building a CSS animation is to defining individual keyframes and naming an animation with a keyframes declaration.
The second step is referencing the keyframes by name using the animation-name property as well as adding animation-duration and other optional animation properties to control the animation's behavior.
However, it is not necessary to define the keyframes rules before referencing or applying it. The following example will show you how to animate a div box horizontally from one position to another using the CSS3 animation feature.
Code pdf of image slider with html , css & javascript −
Responsive Forms : A mobile responsive form, or responsive form, provides an optimal viewing and interaction experience across a wide range of devices, from desktop to mobile. Responsive forms offer easy reading and navigation.
CSS Form Code
UNIT 1 : I O T
UNIT 2 : I O T
MY NOTES ON IOT
