1 00:00:00,000 --> 00:00:03,719 Instructor: Hey guys, welcome to the introduction 2 00:00:03,719 --> 00:00:05,910 to CSS section. 3 00:00:05,910 --> 00:00:07,740 And in this very first lesson 4 00:00:07,740 --> 00:00:10,620 we're gonna be introducing you to CSS. 5 00:00:10,620 --> 00:00:13,440 You'll be learning what it is, how it works 6 00:00:13,440 --> 00:00:16,650 and why we need it to be able to style our websites 7 00:00:16,650 --> 00:00:19,560 and make them look beautiful. 8 00:00:19,560 --> 00:00:21,630 What exactly is CSS? 9 00:00:21,630 --> 00:00:25,920 Well, it stands for cascading style sheets. 10 00:00:25,920 --> 00:00:29,820 It kind of conjures up the image of a cascade, right? 11 00:00:29,820 --> 00:00:33,690 And a cascade is simply like a waterfall. 12 00:00:33,690 --> 00:00:36,330 You have water at one level that then drops 13 00:00:36,330 --> 00:00:40,260 down through a waterfall into another level. 14 00:00:40,260 --> 00:00:41,190 And we're gonna see 15 00:00:41,190 --> 00:00:44,700 as we start to use these cascading style sheets 16 00:00:44,700 --> 00:00:47,160 why that analogy is so apt. 17 00:00:47,160 --> 00:00:50,730 Because the way that the style is applied cascades 18 00:00:50,730 --> 00:00:52,200 like a waterfall. 19 00:00:52,200 --> 00:00:54,120 We start from the most general 20 00:00:54,120 --> 00:00:58,500 all the way down to the most specific styling requirements 21 00:00:58,500 --> 00:00:59,940 and we're going to see that 22 00:00:59,940 --> 00:01:03,990 in use as we use these cascading style sheets. 23 00:01:03,990 --> 00:01:07,920 The other part of this name is the style sheet. 24 00:01:07,920 --> 00:01:11,790 A style sheet is a type of language similar 25 00:01:11,790 --> 00:01:16,790 to how we had the HTML, which is a markup language. 26 00:01:17,280 --> 00:01:21,540 That's what the ML part of HTML stands for. 27 00:01:21,540 --> 00:01:23,640 We have the style sheet 28 00:01:23,640 --> 00:01:26,610 which is what the SS part stands for. 29 00:01:26,610 --> 00:01:29,401 And this is a language that allows us to 30 00:01:29,401 --> 00:01:33,390 specify how things should look in our website. 31 00:01:33,390 --> 00:01:37,050 And there are many different types of style sheet languages 32 00:01:37,050 --> 00:01:38,700 the one that's most important 33 00:01:38,700 --> 00:01:40,380 and what we are gonna be learning all 34 00:01:40,380 --> 00:01:43,890 about in this section is the cascading style sheet. 35 00:01:43,890 --> 00:01:47,400 But there's also others like Sass, which stands 36 00:01:47,400 --> 00:01:52,260 for Syntactically Awesome Style Sheet, and Less 37 00:01:52,260 --> 00:01:57,260 which stands for Leaner CSS and many, many others. 38 00:01:57,390 --> 00:02:00,060 But the most important one that every 39 00:02:00,060 --> 00:02:03,810 web developer needs to know is CSS. 40 00:02:03,810 --> 00:02:06,630 And that's what we're gonna be focusing on today. 41 00:02:06,630 --> 00:02:09,840 So why did we need CSS? 42 00:02:09,840 --> 00:02:13,080 Where did it come from and what exactly is the history 43 00:02:13,080 --> 00:02:14,370 of this whole thing? 44 00:02:14,370 --> 00:02:17,640 Well, in the very beginning, when the internet was very 45 00:02:17,640 --> 00:02:19,920 very new, there was no CSS. 46 00:02:19,920 --> 00:02:22,170 There was only HTML. 47 00:02:22,170 --> 00:02:25,140 And one of the things that developers started wanting to 48 00:02:25,140 --> 00:02:28,710 do is they wanted to style their website and make it 49 00:02:28,710 --> 00:02:31,920 look the way they wanted to, but they were really 50 00:02:31,920 --> 00:02:34,110 really limited by HTML. 51 00:02:34,110 --> 00:02:39,110 And this is a now famous email sent by Marc Andreessen 52 00:02:40,050 --> 00:02:42,720 who is the founder of Mosaic, which is one 53 00:02:42,720 --> 00:02:46,770 of the earliest internet browsers who later found Netscape 54 00:02:46,770 --> 00:02:50,790 and now the very famous Andreessen Horowitz VC fund. 55 00:02:50,790 --> 00:02:54,690 And in his email, he famously said that the answer he has 56 00:02:54,690 --> 00:02:56,850 for so many developers who want to 57 00:02:56,850 --> 00:02:59,850 simply control what their documents look like, 58 00:02:59,850 --> 00:03:02,970 meaning what their websites look like 59 00:03:02,970 --> 00:03:04,290 in a way that would be trivial 60 00:03:04,290 --> 00:03:06,690 say in Microsoft Word, his answer 61 00:03:06,690 --> 00:03:09,660 to these developers is just, sorry, you're screwed. 62 00:03:09,660 --> 00:03:11,499 There is no way to do it very easily 63 00:03:11,499 --> 00:03:14,700 at that point in HTML. 64 00:03:14,700 --> 00:03:17,460 That's why all the website looks pretty much the same 65 00:03:17,460 --> 00:03:18,540 pretty boring. 66 00:03:18,540 --> 00:03:20,610 And there was no variation. 67 00:03:20,610 --> 00:03:21,930 So what happened next? 68 00:03:21,930 --> 00:03:25,410 Well, the W3 consortium responded 69 00:03:25,410 --> 00:03:30,330 by releasing a new version of HTML, HTML 3.2. 70 00:03:30,330 --> 00:03:32,430 And this came out in 1997 71 00:03:32,430 --> 00:03:35,400 so it was still in the very early days of the internet. 72 00:03:35,400 --> 00:03:38,940 And what this 3.2 HTML allowed was 73 00:03:38,940 --> 00:03:43,940 it introduced new HTML tags, such as the font tag 74 00:03:44,010 --> 00:03:46,770 which allows you to define the font size, the color 75 00:03:46,770 --> 00:03:50,010 and the font face, so the type 76 00:03:50,010 --> 00:03:53,280 of font you would want to use for your document. 77 00:03:53,280 --> 00:03:57,750 Similarly, there was also the color attribute for font. 78 00:03:57,750 --> 00:04:00,270 There was the face attribute, the size attribute 79 00:04:00,270 --> 00:04:02,640 and these attributes allow you to change all sorts 80 00:04:02,640 --> 00:04:06,840 of things about the way the text looks on your website. 81 00:04:06,840 --> 00:04:08,970 And then there was also the center element 82 00:04:08,970 --> 00:04:12,360 which allows you to format your document 83 00:04:12,360 --> 00:04:16,680 and define how it would be laid out on the screen. 84 00:04:16,680 --> 00:04:18,322 Now, what you'll notice in all three 85 00:04:18,322 --> 00:04:23,322 of these webpages is the deprecated symbol next to it. 86 00:04:23,850 --> 00:04:26,520 All of these are deprecated, which 87 00:04:26,520 --> 00:04:29,550 in programming lingo simply means you should 88 00:04:29,550 --> 00:04:34,410 no longer be using these attributes and elements. 89 00:04:34,410 --> 00:04:37,980 And the reason for this is because as you can imagine 90 00:04:37,980 --> 00:04:41,940 our HTML is supposed to be for content. 91 00:04:41,940 --> 00:04:46,560 Now, if you add in a ton of styling into all of that content 92 00:04:46,560 --> 00:04:50,580 you tell the website how it should be centered 93 00:04:50,580 --> 00:04:52,230 how it should be laid out 94 00:04:52,230 --> 00:04:55,950 how the font should look, what color it should be 95 00:04:55,950 --> 00:04:57,960 what kind of border your tables should have 96 00:04:57,960 --> 00:05:01,618 and whole bunch of other styling effectively 97 00:05:01,618 --> 00:05:06,618 then this is going to massively clutter up all of your HTML. 98 00:05:07,140 --> 00:05:10,530 And you can imagine this is a really, really short website 99 00:05:10,530 --> 00:05:13,380 and it's already got so much junk in it that we can't really 100 00:05:13,380 --> 00:05:16,920 tell what exactly is the structure and the content 101 00:05:16,920 --> 00:05:18,180 of the website. 102 00:05:18,180 --> 00:05:21,930 And if you extend this to a larger website and you just 103 00:05:21,930 --> 00:05:25,440 wanna do some simple things like give it some colors 104 00:05:25,440 --> 00:05:30,240 or put things into the center, then your whole HTML file 105 00:05:30,240 --> 00:05:32,340 is gonna be many, many, many thousands 106 00:05:32,340 --> 00:05:35,730 of lines long, and it's impossible to differentiate 107 00:05:35,730 --> 00:05:38,370 the content from the styling. 108 00:05:38,370 --> 00:05:40,454 So what happened next? 109 00:05:40,454 --> 00:05:45,454 Well, in 1996, a new recommendation was proposed 110 00:05:46,530 --> 00:05:49,140 by the W3 Consortium 111 00:05:49,140 --> 00:05:52,477 and this was led by Hakon Wium... 112 00:05:54,180 --> 00:05:56,550 how calm... 113 00:05:56,550 --> 00:05:58,440 How come... 114 00:05:58,440 --> 00:06:00,390 By how come. 115 00:06:00,390 --> 00:06:04,350 And he's basically the father of the cascading style sheet. 116 00:06:04,350 --> 00:06:07,440 And what this recommendation allows us to do is to 117 00:06:07,440 --> 00:06:11,490 allow us to attach style such as fonts, colors 118 00:06:11,490 --> 00:06:15,780 and spacing to our HTML documents. 119 00:06:15,780 --> 00:06:19,050 And this is the breakthrough that allowed us to 120 00:06:19,050 --> 00:06:23,220 separate our styling from our content. 121 00:06:23,220 --> 00:06:27,210 And as in many different situations, a separation 122 00:06:27,210 --> 00:06:30,600 of concerns so that somebody is responsible 123 00:06:30,600 --> 00:06:32,430 for putting together the car headlights 124 00:06:32,430 --> 00:06:35,010 and somebody else is responsible for dealing 125 00:06:35,010 --> 00:06:39,720 with the wheels rather than one person making an entire car. 126 00:06:39,720 --> 00:06:42,450 This kind of modularity, as you'll see 127 00:06:42,450 --> 00:06:45,780 in coming lessons, is super important, not just 128 00:06:45,780 --> 00:06:50,280 in manufacturing and in real life, but also in programming. 129 00:06:50,280 --> 00:06:54,102 If you wanna see what CSS is able to achieve 130 00:06:54,102 --> 00:06:57,630 I've built this website for you to be able to do that. 131 00:06:57,630 --> 00:07:01,310 If you go over to appbrewery.github.io and then 132 00:07:01,310 --> 00:07:06,310 /just-add-css, you should be able to see this website. 133 00:07:06,720 --> 00:07:08,400 And when you first go over there 134 00:07:08,400 --> 00:07:11,970 you'll see that it's just a very, very simple website. 135 00:07:11,970 --> 00:07:13,110 Pretty bland. 136 00:07:13,110 --> 00:07:15,390 All it's got is HTML. 137 00:07:15,390 --> 00:07:16,620 And now if we go ahead 138 00:07:16,620 --> 00:07:21,270 and press this button to toggle and turn on CSS 139 00:07:21,270 --> 00:07:24,270 then you'll see the entire website transform 140 00:07:24,270 --> 00:07:26,520 and look way more beautiful. 141 00:07:26,520 --> 00:07:29,310 It's now got different fonts, different colors 142 00:07:29,310 --> 00:07:32,550 and different layouts, but you'll notice that 143 00:07:32,550 --> 00:07:37,530 if you go ahead and right click and view the page source 144 00:07:37,530 --> 00:07:41,580 in these two versions, the HTML does not change at all. 145 00:07:41,580 --> 00:07:44,280 So let's toggle our CSS back 146 00:07:44,280 --> 00:07:47,520 and then let's go ahead and view page Source again. 147 00:07:47,520 --> 00:07:49,770 You'll see that in these two versions 148 00:07:49,770 --> 00:07:52,050 as you see me switch it on screen 149 00:07:52,050 --> 00:07:57,050 nothing changes in our index.html. 150 00:07:57,090 --> 00:08:00,870 The only thing that is different is the CSS 151 00:08:00,870 --> 00:08:02,490 that gets added. 152 00:08:02,490 --> 00:08:06,000 Now don't worry too much about the script tags down here 153 00:08:06,000 --> 00:08:08,940 or how we've created our buttons. 154 00:08:08,940 --> 00:08:10,200 We're gonna learn all 155 00:08:10,200 --> 00:08:13,200 of that later on when we learn JavaScript. 156 00:08:13,200 --> 00:08:15,795 But I created this website so that you can play around 157 00:08:15,795 --> 00:08:17,970 with toggling the CSS on 158 00:08:17,970 --> 00:08:22,970 and off to see how it can transform a simple HTML website 159 00:08:23,130 --> 00:08:27,210 without touching any of the code inside the HTML. 160 00:08:27,210 --> 00:08:31,050 And all that we're doing is adding style to our website 161 00:08:31,050 --> 00:08:34,440 in a completely separate language, 162 00:08:34,440 --> 00:08:36,419 the Cascading style sheet. 163 00:08:36,419 --> 00:08:38,820 To learn more about how CSS works 164 00:08:38,820 --> 00:08:41,270 head over to the next lesson where we're gonna get started 165 00:08:41,270 --> 00:08:43,653 styling up a website.