Open CSS File

CSS (Cascading Style Sheets) formatting and extension files are encrypted files that select elements on your page and control their display.

This is so, think of the HTML of your custom template as the bones of the website and the CSS as the skin.

This is how a CSS file works, it is basically the 'presentation and clothing' of a website.

Thus, the elements of the web page created with HTML will be given the desired appearance using CSS: colors, spaces between elements, fonts, thus separating the structure from the presentation.

This separation between the structure and the presentation is very important, since it allows that only changing the CSS completely modifies the appearance of a web page.

This makes it possible, among other things, for users to use custom style sheets (such as high-contrast or accessibility style sheets).

CSS is a standard

The W3C defines the specifications of the CSS standard.

Browsers then try to implement those specifications, so that web pages look the same in all of them.

Browsers, as they advance, comply more and better with the CSS standard.

For this reason, web pages must be laid out following the CSS standard and not the specifications of a specific browser.

We must also try to keep the browser updated, since as they comply with the standard, they add features that they did not have before.

CSS is also a language

The CSS language uses a simple syntax with numerous English keywords to specify style property names.

CSS selectors include elements of specific types, elements specified by attribute (id and class), and elements that depend on their relative location or are nested inside others in the document tree.

Software to open and work with a CSS file

As it is a text type file, CSS can be created, opened and edited with practically any known text editor, however it is recommended to use an editor designed to work with HTML, since highlighting is important when to edit those files:

• Visual Studio Code
• Geany
• Notepad++