ASCII text
title: Let's write more semantic CSS topics: ["web", "css", "html"] ---
You probably wrote something like this at least once in your life:
<div class="card card--rounded card--primary">
<div class="card__image-container">
<img src="image.jpg" alt="A nice image" class="card__image">
<span class="card__image-caption">A nice image</span>
</div>
<div class="card__content">
<div class="card__header">
<div class="card__title">Hello, world!</div>
</div>
<p class="card__text">
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</p>
</div>
<div class="card__footer">
<button class="btn btn--primary btn--raised btn--accent card__button card__button--primary">Click me!</button>
<button class="btn btn--secondary btn--raised btn--accent card__button card__button--secondary">Click me!</button>
</div>
</div>
Or this:
<div class="max-w-sm rounded overflow-hidden shadow-lg">
<div>
<img class="w-full" src="image.jpg" alt="A nice image">
<span class="text-gray-500 text-base">A nice image</span>
</div>
<div class="px-6 py-4">
<div>
<div class="font-bold text-xl mb-2">Hello, world!</div>
</div>
<p class="text-gray-700 text-base">
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</p>
</div>
<div class="px-6 py-4">
<button class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded">Click me!</button>
<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>
</div>
</div>
The second one is an adapted example from the Tailwind CSS docs. The first one is a variant that uses BEM instead. Both of them have many problems.
HTML has got over 100 elements you could use to structure your content. These examples use only
5: div, span, p, img, and button. This is not a problem in itself for small components,
but it can indicate one. Using div and span for everything means you're misusing HTML. This
is wrong: don't overlook HTML. JS or CSS may be more interesting, but the document language of
the WWW is HTML.
The first example uses classes in place of elements. This creates extra work for both the HTML and CSS author. The CSS still mirrors the HTML structure, and the HTML is much more verbose than it needs to be. The word "button" or "btn" appears 8 times for each button. Ideally, it should appear two times: once in the opening tag and once in the closing tag.
The second example intentionally has the same markup tree as the first one. However, the classes
changed a lot. Tailwind uses classes instead of CSS rules. It leads to repetition. If you don't
want to repeat, you use components. But what if you don't do components? Then use @apply in
CSS. Yes, CSS. So you're basically writing CSS only with a different syntax and less flexibility.
A Simpler Way
Let's strip the classes and focus on the markup tree for now. The two examples are identical in this regard.
<div>
<div>
<img src="image.jpg" alt="A nice image">
<span>A nice image</span>
</div>
<div>
<div>
<div>Hello, world!</div>
</div>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</p>
</div>
<div>
<button>Click me!</button>
<button>Click me!</button>
</div>
</div>
Now you see what I said? This tree is not semantic at all. Let's find the appropriate elements for each generic one.
<article>
<figure>
<img src="image.jpg" alt="A nice image">
<figcaption>A nice image</figcaption>
</figure>
<section>
<header>
<h2>Hello, world!</h2>
</header>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</p>
</section>
<menu>
<button>Click me!</button>
<button>Click me!</button>
</menu>
</article>
In case you're not familiar with the new elements, the quick meaning is:
article - a self-contained piece of content that makes sense independently from the rest of the page
figure - a piece of content that is referenced from the main content, but can stand alone
figcaption - a caption for a
figure's other content (optional)section - a thematic grouping of content, typically with a heading
header - header for the document or a smaller part of it, can include context, navigation or information about the content
h2 - a second-level section heading (you probably knew this one already)
menu - a list of commands available to take on a specific part of the content
Please read the MDN articles I linked if you want to know more about these elements.
Depending on the other needs of your website or application, you will probably need to add a few classes. However, unlike the other examples, classes should be used as little as possible. Let's remember some things from the examples:
The article is supposed to be a card and styled as such.
The first button is the primary action, and the second one is the secondary action.
In this site, let's say not all articles are cards, but since this one is a card, we'll classify it as such. Let's also say that the secondary buttons are more common, this means we'll add a class to the primary button and style that later.
<article class="card">
<figure>
<img src="image.jpg" alt="A nice image">
<figcaption>A nice image</figcaption>
</figure>
<section>
<header>
<h2>Hello, world!</h2>
</header>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
</p>
</section>
<menu>
<button class="button-primary">Click me!</button>
<button>Click me!</button>
</menu>
</article>
Now, let's write a basic stylesheet for this. It won't look exactly like the second example for
the sake of simplicity, but it could easily be made to look like that. We're going to use a CSS
selector you've probably only seen in resets and to set the font on the html element, the
tag selector. We're also going to use some new CSS smarts to make the styles more maintainable.
html, button, input, select, textarea {
font-family: system-ui, sans-serif;
}
article.card {
background-color: whitesmoke;
border-radius: 12px;
box-shadow: 0 0 4px #00000040;
display: flex;
flex-direction: column;
gap: 1rem;
overflow: hidden;
}
figure {
display: flex;
flex-direction: column;
gap: 0.25rem;
}
figure > img {
width: 100%;
height: auto;
}
figcaption {
font-style: italic;
opacity: 0.875;
}
article.card > section {
padding-left: 1rem;
padding-right: 1rem;
}
article.card > menu, menu.buttonbox {
display: flex;
gap: 1rem;
justify-content: flex-end;
}
button, .button, /* provide alternative where it makes sense, since we may want to make something else look like a button */
input:is([type="button"], [type="submit"], [type="reset"]) {
background-color: white;
color: orange;
border: 4px solid currentColor;
padding: 0.5rem 1rem;
display: inline-flex;
align-items: center;
gap: 0.5rem;
border: none;
border-radius: 4px; /* Border radii are a decoration so pixels are fine */
}
:is(button, .button, input:is([type="button"], [type="submit"], [type="reset"])).button-primary {
background-color: orange;
color: white;
}
Observations:
We provide alternatives for some tag selectors where it makes sense, in case we want to make something else look like a button. However, we don't force using both when it's already clear:
<button>will produce a styled button, same as<a class="button">.<button class="button">is redundant.The
>child selector is used to avoid leaking styles in more complex nested layouts.We use the
:is()pseudo-class to group selectors that have the same styles. This is a new feature in CSS and it saves us from writing an enormous amount of combinations.
Conclusion
Now, writing HTML is much easier: the CSS will adapt to what you intended to describe. The CSS is also much easier to maintain: the style can be changed easily without changing the HTML. The elements are always styled automatically, and you can copy-paste a snippet of plain HTML and have it magically match the rest of your site.
A more complete framework for this could add some layout container utilities. For example, a
grid class that makes the element a grid container and uses --width and --gap custom
properties to position the children. There could also be layout elements to use in place of
divs like x-hbox and x-vbox that are flex containers. This would indicate the default style,
and an additional class or ID would be used to make them responsive as well. Utility classes
aren't bad, but they should be used for the things that can't cause repetition - which side a
dialogue should emerge from, or whether to add padding in a generic row container.
Frameworks Using Semantic CSS
Pico CSS - does it very well, I should take some inspiration from it
Water.css - a very minimalistic CSS framework, primarily intended for publishing, but also includes interactive elements
MVP.css - a basic stylesheet for plain HTML made for any site to look acceptable
The roundabout also uses semantic CSS. Once the API is stabilised a little the CSS will be released as a framework.
You might not even need a framework.
1
---
2
title: Let's write more semantic CSS
3
topics: ["web", "css", "html"]
4
---
5
You probably wrote something like this at least once in your life:
7
```html
8
<div class="card card--rounded card--primary">
9
<div class="card__image-container">
10
<img src="image.jpg" alt="A nice image" class="card__image">
11
<span class="card__image-caption">A nice image</span>
12
</div>
13
<div class="card__content">
14
<div class="card__header">
15
<div class="card__title">Hello, world!</div>
16
</div>
17
<p class="card__text">
18
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
19
</p>
20
</div>
21
<div class="card__footer">
22
<button class="btn btn--primary btn--raised btn--accent card__button card__button--primary">Click me!</button>
23
<button class="btn btn--secondary btn--raised btn--accent card__button card__button--secondary">Click me!</button>
24
</div>
25
</div>
26
```
27
Or this:
28
```html
29
<div class="max-w-sm rounded overflow-hidden shadow-lg">
30
<div>
31
<img class="w-full" src="image.jpg" alt="A nice image">
32
<span class="text-gray-500 text-base">A nice image</span>
33
</div>
34
<div class="px-6 py-4">
35
<div>
36
<div class="font-bold text-xl mb-2">Hello, world!</div>
37
</div>
38
<p class="text-gray-700 text-base">
39
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
40
</p>
41
</div>
42
<div class="px-6 py-4">
43
<button class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded">Click me!</button>
44
<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>
45
</div>
46
</div>
47
```
48
The second one is an adapted example from the **Tailwind** CSS docs. The first one is a variant that
50
uses **BEM** instead. Both of them have *many* problems.
51
HTML has got over 100 elements you could use to structure your content. These examples use only
53
5: `div`, `span`, `p`, `img`, and `button`. This is not a problem in itself for small components,
54
but it can indicate one. Using `div` and `span` for everything means you're misusing HTML. This
55
is wrong: don't overlook HTML. JS or CSS may be more interesting, but the document language of
56
the WWW is HTML.
57
The first example uses classes in place of elements. This creates extra work for both the HTML
59
and CSS author. The CSS still mirrors the HTML structure, and the HTML is much more verbose than
60
it needs to be. The word "button" or "btn" appears 8 times for each button. Ideally, it should
61
appear two times: once in the opening tag and once in the closing tag.
62
The second example intentionally has the same markup tree as the first one. However, the classes
64
changed a lot. Tailwind uses classes instead of CSS rules. It leads to repetition. If you don't
65
want to repeat, you use components. But what if you don't do components? Then use `@apply` in
66
CSS. Yes, CSS. So you're basically writing CSS only with a different syntax and less flexibility.
67
A Simpler Way
69
-------------
70
Let's strip the classes and focus on the markup tree for now. The two examples are identical in
72
this regard.
73
```html
75
<div>
76
<div>
77
<img src="image.jpg" alt="A nice image">
78
<span>A nice image</span>
79
</div>
80
<div>
81
<div>
82
<div>Hello, world!</div>
83
</div>
84
<p>
85
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
86
</p>
87
</div>
88
<div>
89
<button>Click me!</button>
90
<button>Click me!</button>
91
</div>
92
</div>
93
```
94
Now you see what I said? This tree is not semantic at all. Let's find the appropriate elements for
96
each generic one.
97
```html
99
<article>
100
<figure>
101
<img src="image.jpg" alt="A nice image">
102
<figcaption>A nice image</figcaption>
103
</figure>
104
<section>
105
<header>
106
<h2>Hello, world!</h2>
107
</header>
108
<p>
109
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
110
</p>
111
</section>
112
<menu>
113
<button>Click me!</button>
114
<button>Click me!</button>
115
</menu>
116
</article>
117
```
118
In case you're not familiar with the new elements, the quick meaning is:
120
* [article](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/article) - a self-contained
122
piece of content that makes sense independently from the rest of the page
123
* [figure](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/figure) - a piece of content
124
that is referenced from the main content, but can stand alone
125
* [figcaption](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/figcaption) - a caption
126
for a `figure`'s other content (optional)
127
* [section](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/section) - a thematic grouping
128
of content, typically with a heading
129
* [header](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/header) - header for the
130
document or a smaller part of it, can include context, navigation or information about the
131
content
132
* [h2](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/h2) - a second-level section
133
heading (you probably knew this one already)
134
* [menu](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/menu) - a list of commands
135
available to take on a specific part of the content
136
Please read the MDN articles I linked if you want to know more about these elements.
138
Depending on the other needs of your website or application, you will probably need to add a few
140
classes. However, unlike the other examples, classes should be used as little as possible. Let's
141
remember some things from the examples:
142
* The article is supposed to be a card and styled as such.
144
* The first button is the primary action, and the second one is the secondary action.
145
In this site, let's say not all articles are cards, but since this one *is* 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
```html
151
<article class="card">
152
<figure>
153
<img src="image.jpg" alt="A nice image">
154
<figcaption>A nice image</figcaption>
155
</figure>
156
<section>
157
<header>
158
<h2>Hello, world!</h2>
159
</header>
160
<p>
161
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
162
</p>
163
</section>
164
<menu>
165
<button class="button-primary">Click me!</button>
166
<button>Click me!</button>
167
</menu>
168
</article>
169
```
170
Now, let's write a basic stylesheet for this. It won't look exactly like the second example for
172
the sake of simplicity, but it could easily be made to look like that. We're going to use a CSS
173
selector you've probably only seen in resets and to set the font on the `html` element, the
174
tag selector. We're also going to use some new CSS smarts to make the styles more maintainable.
175
```css
177
html, button, input, select, textarea {
178
font-family: system-ui, sans-serif;
179
}
180
article.card {
181
background-color: whitesmoke;
182
border-radius: 12px;
183
box-shadow: 0 0 4px #00000040;
184
display: flex;
185
flex-direction: column;
186
gap: 1rem;
187
overflow: hidden;
188
}
189
figure {
190
display: flex;
191
flex-direction: column;
192
gap: 0.25rem;
193
}
194
figure > img {
195
width: 100%;
196
height: auto;
197
}
198
figcaption {
199
font-style: italic;
200
opacity: 0.875;
201
}
202
article.card > section {
203
padding-left: 1rem;
204
padding-right: 1rem;
205
}
206
article.card > menu, menu.buttonbox {
207
display: flex;
208
gap: 1rem;
209
justify-content: flex-end;
210
}
211
button, .button, /* provide alternative where it makes sense, since we may want to make something else look like a button */
212
input:is([type="button"], [type="submit"], [type="reset"]) {
213
background-color: white;
214
color: orange;
215
border: 4px solid currentColor;
216
padding: 0.5rem 1rem;
217
display: inline-flex;
218
align-items: center;
219
gap: 0.5rem;
220
border: none;
221
border-radius: 4px; /* Border radii are a decoration so pixels are fine */
222
}
223
:is(button, .button, input:is([type="button"], [type="submit"], [type="reset"])).button-primary {
224
background-color: orange;
225
color: white;
226
}
227
```
228
Observations:
230
* We provide alternatives for some tag selectors where it makes sense, in case we want to make
231
something else look like a button. However, we don't force using both when it's already clear:
232
`<button>` will produce a styled button, same as `<a class="button">`. `<button class="button">`
233
is redundant.
234
* The `>` child selector is used to avoid leaking styles in more complex nested layouts.
235
* We use the `:is()` pseudo-class to group selectors that have the same styles. This is a new
236
feature in CSS and it saves us from writing an enormous amount of combinations.
237
Conclusion
239
----------
240
Now, writing HTML is much easier: the CSS will adapt to what you intended to describe. The CSS
242
is also much easier to maintain: the style can be changed easily without changing the HTML. The
243
elements are always styled automatically, and you can copy-paste a snippet of plain HTML
244
and have it magically match the rest of your site.
245
A more complete framework for this could add some layout container utilities. For example, a
247
`grid` class that makes the element a grid container and uses `--width` and `--gap` custom
248
properties to position the children. There could also be layout *elements* to use in place of
249
divs like `x-hbox` and `x-vbox` that are flex containers. This would indicate the default style,
250
and an additional class or ID would be used to make them responsive as well. Utility classes
251
aren't bad, but they should be used for the things that can't cause repetition - which side a
252
dialogue should emerge from, or whether to add padding in a generic row container.
253
Frameworks Using Semantic CSS
255
------------------------------
256
* [Pico CSS](https://picocss.com/) - does it very well, I should take some inspiration from it
258
* [Water.css](https://watercss.kognise.dev/) - a very minimalistic CSS framework, primarily intended
259
for publishing, but also includes interactive elements
260
* [MVP.css](https://andybrewer.github.io/mvp/) - a basic stylesheet for plain HTML made for any
261
site to look acceptable
262
* The roundabout also uses semantic CSS. Once the API is stabilised a little the CSS will be
263
released as a framework.
264
* You might not even need a framework.
265