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In this video, you'll learn why CSS is an essential part of web design and development.
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As you might have learned in a previous course, a Web page is made up of
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three different layers that work together to deliver an experience to the user.
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There's a content [SOUND] layer, a presentation layer, and
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a behavior [SOUND] layer.
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While [SOUND] HTML provides the content layer, and
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the [SOUND] behavior layer is normally handled by JavaScript for real-time user
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interaction, CSS is what handles the presentation layer of a Web page.
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It's what makes our HTML look pretty.
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[SOUND] You see, back in the early days of the Web before CSS was introduced,
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developers would have to [SOUND] embed presentational tags and
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attributes into HTML to control the design of a Web page.
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And many of those tags were proprietary tags that only worked for
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certain browsers, usually for the browser vendors that created them.
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So, providing support and
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maintaining a consistent look for every browser was nearly impossible.
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Remember, HTML was never intended to be a presentation language, so
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it made it difficult and impractical to create Web sites where the content of
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each HTML page was separate from the presentation.
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Imagine having to manually edit tens or
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hundreds of HTML files to make a single styling change.
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So there had to be a more efficient way of doing this, right?
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Well, because of all the problems that came with this sort of
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ad hoc way of styling Web pages,
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CSS was finally introduced in HTML4 to help solve many of these problems.
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With CSS, web authors finally had a way to express their designs without having to
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add new HTML tags.
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And by separating the content from the presentation,
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[SOUND] CSS made the development and
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maintenance of Web sites more efficient [SOUND] because the styles written in
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a single CSS file could be [SOUND] shared across multiple Web pages.
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Now, over the years, [SOUND] CSS has also improved the accessibility of web
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content because it's allowed us to adapt our content to [SOUND] various devices,
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[SOUND] screen sizes, and resolutions.
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And what's exciting is that CSS continues to evolve.
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As you'll soon learn, today's CSS features are becoming closer to
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tools we'd normally use in a graphics editor like Photoshop.
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That's because CSS3, the latest evolution of CSS,
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has introduced many in-browser design features like rounded corners,
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box shadows, gradients, animations, as well as new layout features like Flexbox.
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So, us designers and developers now have more power and
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flexibility when designing and building for the web.
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It's a great time to be learning CSS.
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