How To Add CSS

When a browser reads a style sheet, it will format the HTML document according to the information in the style sheet.

Three Ways to Insert CSS

There are three ways of inserting a style sheet:

External CSS

With an external style sheet, you can change the look of an entire website by changing just one file!

Each HTML page must include a reference to the external style sheet file inside the element, inside the head section.

Example

External styles are defined within the element, inside the section of an HTML page:

This is a heading

This is a paragraph.

An external style sheet can be written in any text editor, and must be saved with a .css extension.

The external .css file should not contain any HTML tags.

Here is how the «mystyle.css» file looks:

«mystyle.css»

body <
background-color: lightblue;
>

h1 color: navy;
margin-left: 20px;
>

Note: Do not add a space between the property value (20) and the unit (px):
Incorrect (space): margin-left: 20 px;
Correct (no space): margin-left: 20px;

Internal CSS

An internal style sheet may be used if one single HTML page has a unique style.

The internal style is defined inside the element, inside the head section.

Example

Internal styles are defined within the element, inside the section of an HTML page:

This is a heading

This is a paragraph.

Inline CSS

An inline style may be used to apply a unique style for a single element.

To use inline styles, add the style attribute to the relevant element. The style attribute can contain any CSS property.

Example

Inline styles are defined within the «style» attribute of the relevant element:

This is a heading

This is a paragraph.

Tip: An inline style loses many of the advantages of a style sheet (by mixing content with presentation). Use this method sparingly.

Multiple Style Sheets

If some properties have been defined for the same selector (element) in different style sheets, the value from the last read style sheet will be used.

Assume that an external style sheet has the following style for the element:

Then, assume that an internal style sheet also has the following style for the element:

Example

If the internal style is defined after the link to the external style sheet, the elements will be «orange»:

Example

However, if the internal style is defined before the link to the external style sheet, the elements will be «navy»:

Cascading Order

What style will be used when there is more than one style specified for an HTML element?

All the styles in a page will «cascade» into a new «virtual» style sheet by the following rules, where number one has the highest priority:

1. Inline style (inside an HTML element)
2. External and internal style sheets (in the head section)
3. Browser default

So, an inline style has the highest priority, and will override external and internal styles and browser defaults.

Ever heard about W3Schools Spaces? Here you can create your own website, or save code snippets for later use, for free.

Источник

CSS: Cascading Style Sheets

Cascading Style Sheets (CSS) is a stylesheet language used to describe the presentation of a document written in HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS describes how elements should be rendered on screen, on paper, in speech, or on other media.

CSS is among the core languages of the open web and is standardized across Web browsers according to W3C specifications. Previously, the development of various parts of CSS specification was done synchronously, which allowed the versioning of the latest recommendations. You might have heard about CSS1, CSS2.1, or even CSS3. There will never be a CSS3 or a CSS4; rather, everything is now CSS without a version number.

After CSS 2.1, the scope of the specification increased significantly and the progress on different CSS modules started to differ so much, that it became more effective to develop and release recommendations separately per module. Instead of versioning the CSS specification, W3C now periodically takes a snapshot of the latest stable state of the CSS specification and individual modules progress. CSS modules now have version numbers, or levels, such as CSS Color Module Level 5.

Key resources

If you’re new to web development, be sure to read our CSS basics article to learn what CSS is and how to use it.

Our CSS learning area contains a wealth of tutorials to take you from beginner level to proficiency, covering all the fundamentals.

Our exhaustive CSS reference for seasoned Web developers describes every property and concept of CSS.

Looking to become a front-end web developer?

We have put together a course that includes all the essential information you need to work towards your goal.

Tutorials

Our CSS Learning Area features multiple modules that teach CSS from the ground up — no previous knowledge required.

CSS (Cascading Style Sheets) is used to style and layout web pages — for example, to alter the font, color, size, and spacing of your content, split it into multiple columns, or add animations and other decorative features. This module provides a gentle beginning to your path towards CSS mastery with the basics of how it works, what the syntax looks like, and how you can start using it to add styling to HTML.

This module carries on where CSS first steps left off — now you’ve gained familiarity with the language and its syntax, and got some basic experience with using it, it’s time to dive a bit deeper. This module looks at the cascade and inheritance, all the selector types we have available, units, sizing, styling backgrounds and borders, debugging, and lots more.

The aim here is to provide you with a toolkit for writing competent CSS and help you understand all the essential theory, before moving on to more specific disciplines like text styling and CSS layout.

With the basics of the CSS language covered, the next CSS topic for you to concentrate on is styling text — one of the most common things you’ll do with CSS. Here we look at text styling fundamentals, including setting font, boldness, italics, line and letter spacing, drop shadows, and other text features. We round off the module by looking at applying custom fonts to your page, and styling lists and links.

At this point we’ve already looked at CSS fundamentals, how to style text, and how to style and manipulate the boxes that your content sits inside. Now it’s time to look at how to place your boxes in the right place in relation to the viewport, and to each other. We have covered the necessary prerequisites so we can now dive deep into CSS layout, looking at different display settings, modern layout tools like flexbox, CSS grid, and positioning, and some of the legacy techniques you might still want to know about.

This module provides links to sections of content explaining how to use CSS to solve common problems when creating a web page.

Reference

• CSS reference: This exhaustive reference for seasoned Web developers describes every property and concept of CSS.
• CSS key concepts:
  • The syntax and forms of the language
  • Specificity, inheritance, and the Cascade
  • CSS units and values and functional notations
  • Box model and margin collapse
  • The containing block
  • Stacking and block-formatting contexts
  • Initial, computed, used, and actual values
  • CSS shorthand properties
  • CSS Flexible Box Layout
  • CSS Grid Layout
  • CSS selectors
  • Media queries
  • Animation

  Cookbook

  The CSS layout cookbook aims to bring together recipes for common layout patterns, things you might need to implement in your sites. In addition to providing code you can use as a starting point in your projects, these recipes highlight the different ways layout specifications can be used and the choices you can make as a developer.

  Tools for CSS development

  • You can use the W3C CSS Validation Service to check if your CSS is valid. This is an invaluable debugging tool.
  • Firefox Developer Tools lets you view and edit a page’s live CSS via the Inspector and Style Editor tools.
  • The Web Developer extension for Firefox lets you track and edit live CSS on watched sites.

  Meta bugs

  See also

  • CSS demos: Get a creative boost by exploring examples of the latest CSS technologies in action.
  • Web languages to which CSS is often applied: HTML, SVG, MathML, XHTML, and XML.
  • Stack Overflow questions about CSS

  Found a content problem with this page?

  This page was last modified on Jul 22, 2023 by MDN contributors.

  Your blueprint for a better internet.

  Источник

  How to Work with CSS Style Sheets – the Basics for Beginners

  

  David Clinton

  

  Using HTML tags like , , and so on can help you organize your web page content nicely, but only up to a point.

  HTML-only pages can be pleasant and easy to read – which is hugely important – but, after a while, they all do tend to look the same.

  Cascading style sheets, known universally as CSS, aren’t really sheets, and it can take some work to figure out what «cascading» means. But the markup standard adds real power to your web development work. Let’s look at some of that CSS magic in action.

  This article comes from my Complete LPI Web Development Essentials Study Guide course. If you’d like, you can follow the video version here:

  

  Wrapping Up

  We’ve successfully incorporated CSS code within our HTML and precisely applied CSS styles to our content. Now take a couple of minutes to create something similar for yourself. Make sure you play around with all the values so you completely understand how they work.

  Источник

  Читайте также:  Print whitespace in python