HTML document, Unicode text, UTF-8 text
1
<!DOCTYPE html>
2
<html lang="en">
3
<head>
4
<meta charset="UTF-8">
5
<title>
6
Let's write more semantic CSS
7
</title>
8
<link rel="stylesheet" href="/static/style.css">
9
<meta name="viewport" content="width=device-width, initial-scale=1.0">
10
</head>
11
<body>
12
<header>
13
<nav>
14
<ul>
15
<li><a href="/">Home</a></li>
16
<li><a href="/projects">Projects</a></li>
17
<li><a href="/index">Index</a></li>
18
<li><a href="https://roundabout-host.com/roundabout">Roundabout-host</a></li>
19
</ul>
20
<ul>
21
<li><a href="mailto:root@roundabout-host.com" id="mail-link">root@roundabout-host.com</a></li>
22
</ul>
23
</nav>
24
</header>
25
<main>
26
27
<h1>Let's write more semantic CSS</h1>
28
<div id="article-date">2024-05-18, 09:11:37</div>
29
30
<article class="content-area">
31
<p>You probably wrote something like this at least once in your life:
32
</p><pre data-language="html"><div class="card card--rounded card--primary">
33
<div class="card__image-container">
34
<img src="image.jpg" alt="A nice image" class="card__image">
35
<span class="card__image-caption">A nice image</span>
36
</div>
37
<div class="card__content">
38
<div class="card__header">
39
<div class="card__title">Hello, world!</div>
40
</div>
41
<p class="card__text">
42
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
43
</p>
44
</div>
45
<div class="card__footer">
46
<button class="btn btn--primary btn--raised btn--accent card__button card__button--primary">Click me!</button>
47
<button class="btn btn--secondary btn--raised btn--accent card__button card__button--secondary">Click me!</button>
48
</div>
49
</div>
50
</pre><p>Or this:
51
</p><pre data-language="html"><div class="max-w-sm rounded overflow-hidden shadow-lg">
52
<div>
53
<img class="w-full" src="image.jpg" alt="A nice image">
54
<span class="text-gray-500 text-base">A nice image</span>
55
</div>
56
<div class="px-6 py-4">
57
<div>
58
<div class="font-bold text-xl mb-2">Hello, world!</div>
59
</div>
60
<p class="text-gray-700 text-base">
61
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
62
</p>
63
</div>
64
<div class="px-6 py-4">
65
<button class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded">Click me!</button>
66
<button class="bg-transparent hover:bg-blue-500 text-blue-700 font-semibold hover:text-white py-2 px-4 border border-blue-500 hover:border-transparent rounded">Click me!</button>
67
</div>
68
</div>
69
</pre><p>The second one is an adapted example from the <strong class="emphasis-2">Tailwind</strong> CSS docs. The first one is a variant that
70
uses <strong class="emphasis-2">BEM</strong> instead. Both of them have <em class="emphasis-1">many</em> problems.
71
</p><p>HTML has got over 100 elements you could use to structure your content. These examples use only
72
5: <code>div</code>, <code>span</code>, <code>p</code>, <code>img</code>, and <code>button</code>. This is not a problem in itself for small components,
73
but it can indicate one. Using <code>div</code> and <code>span</code> for everything means you're misusing HTML. This
74
is wrong: don't overlook HTML. JS or CSS may be more interesting, but the document language of
75
the WWW is HTML.
76
</p><p>The first example uses classes in place of elements. This creates extra work for both the HTML
77
and CSS author. The CSS still mirrors the HTML structure, and the HTML is much more verbose than
78
it needs to be. The word "button" or "btn" appears 8 times for each button. Ideally, it should
79
appear two times: once in the opening tag and once in the closing tag.
80
</p><p>The second example intentionally has the same markup tree as the first one. However, the classes
81
changed a lot. Tailwind uses classes instead of CSS rules. It leads to repetition. If you don't
82
want to repeat, you use components. But what if you don't do components? Then use <code>@apply</code> in
83
CSS. Yes, CSS. So you're basically writing CSS only with a different syntax and less flexibility.
84
</p><h2>A Simpler Way</h2><p>Let's strip the classes and focus on the markup tree for now. The two examples are identical in
85
this regard.
86
</p><pre data-language="html"><div>
87
<div>
88
<img src="image.jpg" alt="A nice image">
89
<span>A nice image</span>
90
</div>
91
<div>
92
<div>
93
<div>Hello, world!</div>
94
</div>
95
<p>
96
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
97
</p>
98
</div>
99
<div>
100
<button>Click me!</button>
101
<button>Click me!</button>
102
</div>
103
</div>
104
</pre><p>Now you see what I said? This tree is not semantic at all. Let's find the appropriate elements for
105
each generic one.
106
</p><pre data-language="html"><article>
107
<figure>
108
<img src="image.jpg" alt="A nice image">
109
<figcaption>A nice image</figcaption>
110
</figure>
111
<section>
112
<header>
113
<h2>Hello, world!</h2>
114
</header>
115
<p>
116
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
117
</p>
118
</section>
119
<menu>
120
<button>Click me!</button>
121
<button>Click me!</button>
122
</menu>
123
</article>
124
</pre><p>In case you're not familiar with the new elements, the quick meaning is:
125
</p><ul><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/article">article</a> - a self-contained
126
piece of content that makes sense independently from the rest of the page
127
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/figure">figure</a> - a piece of content
128
that is referenced from the main content, but can stand alone
129
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/figcaption">figcaption</a> - a caption
130
for a <code>figure</code>'s other content (optional)
131
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/section">section</a> - a thematic grouping
132
of content, typically with a heading
133
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/header">header</a> - header for the
134
document or a smaller part of it, can include context, navigation or information about the
135
content
136
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/h2">h2</a> - a second-level section
137
heading (you probably knew this one already)
138
</p></li><li><p><a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Element/menu">menu</a> - a list of commands
139
available to take on a specific part of the content
140
</p></li></ul><p>Please read the MDN articles I linked if you want to know more about these elements.
141
</p><p>Depending on the other needs of your website or application, you will probably need to add a few
142
classes. However, unlike the other examples, classes should be used as little as possible. Let's
143
remember some things from the examples:
144
</p><ul><li><p>The article is supposed to be a card and styled as such.
145
</p></li><li><p>The first button is the primary action, and the second one is the secondary action.
146
</p></li></ul><p>In this site, let's say not all articles are cards, but since this one <em class="emphasis-1">is</em> a card, we'll
147
classify it as such. Let's also say that the secondary buttons are more common, this means we'll
148
add a class to the primary button and style that later.
149
</p><pre data-language="html"><article class="card">
150
<figure>
151
<img src="image.jpg" alt="A nice image">
152
<figcaption>A nice image</figcaption>
153
</figure>
154
<section>
155
<header>
156
<h2>Hello, world!</h2>
157
</header>
158
<p>
159
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
160
</p>
161
</section>
162
<menu>
163
<button class="button-primary">Click me!</button>
164
<button>Click me!</button>
165
</menu>
166
</article>
167
</pre><p>Now, let's write a basic stylesheet for this. It won't look exactly like the second example for
168
the sake of simplicity, but it could easily be made to look like that. We're going to use a CSS
169
selector you've probably only seen in resets and to set the font on the <code>html</code> element, the
170
tag selector. We're also going to use some new CSS smarts to make the styles more maintainable.
171
</p><pre data-language="css">html, button, input, select, textarea {
172
font-family: system-ui, sans-serif;
173
}
174
article.card {
175
background-color: whitesmoke;
176
border-radius: 12px;
177
box-shadow: 0 0 4px #00000040;
178
display: flex;
179
flex-direction: column;
180
gap: 1rem;
181
overflow: hidden;
182
}
183
figure {
184
display: flex;
185
flex-direction: column;
186
gap: 0.25rem;
187
}
188
figure > img {
189
width: 100%;
190
height: auto;
191
}
192
figcaption {
193
font-style: italic;
194
opacity: 0.875;
195
}
196
article.card > section {
197
padding-left: 1rem;
198
padding-right: 1rem;
199
}
200
article.card > menu, menu.buttonbox {
201
display: flex;
202
gap: 1rem;
203
justify-content: flex-end;
204
}
205
button, .button, /* provide alternative where it makes sense, since we may want to make something else look like a button */
206
input:is([type="button"], [type="submit"], [type="reset"]) {
207
background-color: white;
208
color: orange;
209
border: 4px solid currentColor;
210
padding: 0.5rem 1rem;
211
display: inline-flex;
212
align-items: center;
213
gap: 0.5rem;
214
border: none;
215
border-radius: 4px; /* Border radii are a decoration so pixels are fine */
216
}
217
:is(button, .button, input:is([type="button"], [type="submit"], [type="reset"])).button-primary {
218
background-color: orange;
219
color: white;
220
}
221
</pre><p>Observations:
222
</p><ul><li><p>We provide alternatives for some tag selectors where it makes sense, in case we want to make
223
something else look like a button. However, we don't force using both when it's already clear:
224
<code><button></code> will produce a styled button, same as <code><a class="button"></code>. <code><button class="button"></code>
225
is redundant.
226
</p></li><li><p>The <code>></code> child selector is used to avoid leaking styles in more complex nested layouts.
227
</p></li><li><p>We use the <code>:is()</code> pseudo-class to group selectors that have the same styles. This is a new
228
feature in CSS and it saves us from writing an enormous amount of combinations.
229
</p></li></ul><h2>Conclusion</h2><p>Now, writing HTML is much easier: the CSS will adapt to what you intended to describe. The CSS
230
is also much easier to maintain: the style can be changed easily without changing the HTML. The
231
elements are always styled automatically, and you can copy-paste a snippet of plain HTML
232
and have it magically match the rest of your site.
233
</p><p>A more complete framework for this could add some layout container utilities. For example, a
234
<code>grid</code> class that makes the element a grid container and uses <code>--width</code> and <code>--gap</code> custom
235
properties to position the children. There could also be layout <em class="emphasis-1">elements</em> to use in place of
236
divs like <code>x-hbox</code> and <code>x-vbox</code> that are flex containers. This would indicate the default style,
237
and an additional class or ID would be used to make them responsive as well. Utility classes
238
aren't bad, but they should be used for the things that can't cause repetition - which side a
239
dialogue should emerge from, or whether to add padding in a generic row container.
240
</p><h2>Frameworks Using Semantic CSS</h2><ul><li><p><a href="https://picocss.com/">Pico CSS</a> - does it very well, I should take some inspiration from it
241
</p></li><li><p><a href="https://watercss.kognise.dev/">Water.css</a> - a very minimalistic CSS framework, primarily intended
242
for publishing, but also includes interactive elements
243
</p></li><li><p><a href="https://andybrewer.github.io/mvp/">MVP.css</a> - a basic stylesheet for plain HTML made for any
244
site to look acceptable
245
</p></li><li><p>The roundabout also uses semantic CSS. Once the API is stabilised a little the CSS will be
246
released as a framework.
247
</p></li><li><p>You might not even need a framework.
248
</p></li></ul>
249
</article>
250
</main>
252
<footer>
253
<p>Page generated on Tuesday, 21 May 2024 at 17:53:32</p>
254
<p xmlns:cc="http://creativecommons.org/ns#" >This work is marked with <a href="https://creativecommons.org/publicdomain/zero/1.0/?ref=chooser-v1" target="_blank" rel="license noopener noreferrer" style="display:inline-block;">CC0 1.0 Universal</a> (🄍). No rights reserved.</p>
255
<a href="#">Back to top</a>
256
</footer>
257
</body>
258
</html>