Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
The ABCs of CSS You've Likely Never Used
Search
Alicia Sedlock
August 08, 2017
Technology
0
63
The ABCs of CSS You've Likely Never Used
That Conference 2017
Alicia Sedlock
August 08, 2017
Tweet
Share
More Decks by Alicia Sedlock
See All by Alicia Sedlock
How To Fights and Prevent Burnout
aliciasedlock
2
20k
The State of Front-End Testing
aliciasedlock
2
570
The Landscape of Front-End Testing
aliciasedlock
3
1.3k
You Can Make Games
aliciasedlock
1
140
Jumping Into Front-End Testing
aliciasedlock
3
170
Let's Get Testable: An Introduction to Unit Testing
aliciasedlock
4
840
Other Decks in Technology
See All in Technology
いまさら聞けない ABテスト入門
skmr2348
1
200
AI Agentと MCP Serverで実現する iOSアプリの 自動テスト作成の効率化
spiderplus_cb
0
500
GopherCon Tour 概略
logica0419
2
190
生成AIを活用したZennの取り組み事例
ryosukeigarashi
0
200
非エンジニアのあなたもできる&もうやってる!コンテキストエンジニアリング
findy_eventslides
3
910
生成AIとM5Stack / M5 Japan Tour 2025 Autumn 東京
you
PRO
0
210
コンテキストエンジニアリングとは? 考え方と応用方法
findy_eventslides
4
900
BirdCLEF+2025 Noir 5位解法紹介
myso
0
190
E2Eテスト設計_自動化のリアル___Playwrightでの実践とMCPの試み__AIによるテスト観点作成_.pdf
findy_eventslides
0
120
自動テストのコストと向き合ってみた
qa
0
130
Flaky Testへの現実解をGoのプロポーザルから考える | Go Conference 2025
upamune
1
420
Green Tea Garbage Collector の今
zchee
PRO
2
390
Featured
See All Featured
Gamification - CAS2011
davidbonilla
81
5.5k
A Tale of Four Properties
chriscoyier
160
23k
4 Signs Your Business is Dying
shpigford
185
22k
Why Our Code Smells
bkeepers
PRO
339
57k
Measuring & Analyzing Core Web Vitals
bluesmoon
9
610
KATA
mclloyd
32
15k
YesSQL, Process and Tooling at Scale
rocio
173
14k
Bootstrapping a Software Product
garrettdimon
PRO
307
110k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
29
2.6k
How to train your dragon (web standard)
notwaldorf
96
6.3k
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
35
3.2k
Site-Speed That Sticks
csswizardry
11
880
Transcript
The ABCs of CSS Properties You’ve Likely Never Used (Well,
Mostly!) Alicia Sedlock | @aliciability
Hi!
None
What’s your favorite CSS property or module?
None
There’s a lot of CSS I don't know.
A additive-symbols “… specify symbols when the value of a
counter system descriptor is additive.”
@counter-style custom-counter { system: additive; additive-symbol: I 1; } .list
{ list-style: custom-counter; }
@counter-style custom-counter { system: additive; additive-symbol: “>” 3; } .list
{ list-style: customer-counter; }
@counter-style custom-counter { system: additive; additive-symbol: “X” 10, “V” 5,
“I” 1; }
B ::backdrop “…is a box rendered immediately below any
element rendered in fullscreen mode.”
dialog { /* some dialog styles */ } dialog::backdrop {
background: black; opacity: .5; }
None
C caret-color “…sets the color of the caret in
an element.”
input.custom { caret-color: red; }
None
D :default “…represents any user interface element that is
the default among a group of similar elements.”
:default { background-color: pink; } <form> <input type=“button” value=“Button” />
<input type=“submit” /> <input type=“reset” /> </form>
None
E :empty “ ..any element that has no children
at all.”
div { background: lightblue; } div:empty {
background: pink; } <div><!— No content —></div> <div>Hello world!</div> <div> <!— No content —> </div>
None
F ::first-letter “…applies styles to the first letter of
the first line of a block-level element…”
p::first-letter { color: red; font-size: 3em; font-weight: bold;
} <p>The quick brown fox</p>
p::first-letter { color: red; font-size: 3em; font-weight: bold;
} <p> <img src=“fox.jpg” /> The quick brown fox </p>
G grayscale()
.fox1 { filter: grayscale(.95); } .fox2 { filter: grayscale(.55); }
.fox3 { filter: grayscale(.15); }
H hyphens “…how words should be hyphenated when text
wraps across multiple lines.”
<p>That Conference is extreme­ly rad!</p> p { hyphens: none; width:
55px; }
<p>That Conference is extreme­ly rad!</p> p { hyphens: manual; width:
55px; }
<p>That Conference is extreme­ly rad!</p> p { hyphens: auto; width:
55px; }
I :in-range “…matches when the value currently contained inside
an <input> element is inside the range limits specified by the min and max attributes.”
None
<label>Enter a number 1-10</label> <input type="number" min="1" max="10" value="12" />
input:in-range { background-color: rgba(0, 255, 0, 0.25); } input:out-of-range { background-color: rgba(255, 0, 0, 0.25); border: 2px solid red; }
None
J justify-content ONLY ENTRY “…defines how the browser distributes
space between and around content items along the main axis of their container.”
.container { display: flex; justify-content: <value>; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
.container { display: flex; justify-content: flex-start; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
.container { display: flex; justify-content: flex-end; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
.container { display: flex; justify-content: center; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
.container { display: flex; justify-content: space-around; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
.container { display: flex; justify-content: space-between; } <div class=“container”> <div><!—
Content! —></div> <div><!— Content! —></div> <div><!— Content! —></div> </div>
K khz “…represents a frequency dimension, such as the
pitch of a speaking voice.”
p.low { pitch: 105Hz; } em.high { pitch: 135Hz; }
L :lang “…matches elements based on the language the
element is determined to be in.”
<html lang=“en”></html>
<div lang=“en”>Hello, world!</div> <div lang=“fr”>Bonjour, le monde!</div> <div lang=“de”>Hallo, Welt!</div>
:lang(en) { border: 1px solid red; } :lang(fr) {
border: 1px solid blue; } :lang(de) { border: 1px solid black; }
M max-zoom “…sets the maximum zoom factor of a
document defined by the @viewport at- rule."
* { max-zoom: 150%; max-zoom: 2.0; }
N negative “…alters the representation of negative counter values,
by providing a way to specify symbols to be appended or prepended to the counter representation when the value is negative.”
<ul class="list" start="-3"> <li>One</li> <li>Two</li> <li>Three</li> <li>Four</li> <li>Five</li> </ul>
@counter-style negative-counter { system: numeric; symbols: "0" "1" "2" "3"
"4" "5" "6" "7" "8" "9"; negative: "(-" ")"; } .list { list-style: negative-counter; }
None
O object-fit “…how a replaced element, such as an
<img> or <video>, should be resized to fit its container.”
/* Base styles for examples */ img { width: 400px;
height: 500px; border: 5px solid pink; object-fit: <value>; }
None
None
None
None
None
P pointer-events “…specifies under what circumstances a particular graphic
element can become the target of mouse events.”
div { pointer-events: none; }
<div> Lorem ipsum dolor sit amet… </div> <div class="overlay"> I
am an overlay. Try selecting the text behind me. </div>
.overlay { position: absolute; top: 0; left: 40%; background: rgba(0,0,0,.75);
height: 200px; width: 250px; color: white; padding: 1em; pointer-events: auto; }
pointer-events: auto
pointer-events: none
pointer-events: visiblePainted; pointer-events: visibleFill; pointer-events: visibleStroke; pointer-events: visible; pointer-events: painted;
pointer-events: fill; pointer-events: stroke; pointer-events: all;
Q quotes “…indicates how user agents should render quotation
marks.”
<span>According to Groot, <q>I am Groot.</q>.</span> q { quotes:
"**" “**”; } q:before { content: open-quote; } q:after { content: close-quote; }
<span>Peter Quill says <q>I'm pretty sure the answer is <q>I
am Groot</q>.</q></span> q { quotes: ’””’ ‘“”’ “‘’” “‘’”; } q:before { content: open-quote; } q:after { content: close-quote; }
R revert “…rolls back the cascade so that a
property takes on the value it would have had if there were no styles in the current style origin"
None
S suffix “…specifies a symbol that will be appended
to the marker representation.”
<ul class="list"> <li>One</li> <li>Two</li> <li>Three</li> <li>Four</li> <li>Five</li> </ul>
@counter-style counter-options { system: fixed; symbols: A B C D
E F G; suffix: “) ”; } .list { list-style: counter-options; }
None
T tab-size “…used to customize the width of a
tab (U+0009) character.”
pre { tab-size: 4; /* integer values */ tab-size: 2;
tab-size: 10px; /* length values */ tab-size: 2em; }
<pre class=“default"> 	This is a line in pre! 	CSS is
a lot of fun. :) </pre> pre { border: 1px solid black; width: 500px; }
<pre class=“default"> 	This is a line in pre! 	CSS is
a lot of fun. :) </pre> pre { border: 1px solid black; width: 500px; tab-size: 4; }
<pre class=“default"> 	This is a line in pre! 	CSS is
a lot of fun. :) </pre> pre { border: 1px solid black; width: 500px; tab-size: 100px; }
U unset “…resets a property to its inherited value
if it inherits from its parent, and to its initial value if not.”
<p>I want to be blue text!</p> <div class="foo"> <p>I want
to be orange text :(</p> </div> <div class="bar"> <p>I don't want to be orange.</p> </div> .foo { color: orange; } .bar { color: green; } p { color: blue; } .bar p { color: unset; }
None
V vw/vh “Equal to 1% of the width/height of the
viewport's initial containing block.”
W will-change “…provides a way for authors to hint browsers
about the kind of changes to be expected on an element, so that the browser can set up appropriate optimizations ahead of time…”
div { will-change: transform; will-change: opacity; will-change: contents; /* custom-ident
*/ will-change: scroll-behavior; /* custom-ident */ }
A warning on will-change • Intended as a “last resort”
- don’t prematurely optimize • Meant to be used sparingly
X Y
* { xtreme: ‘heck-yeah’; }
* { yolo: 100; }
Z z-index “… specifies the z-order of a positioned element
and its descendants.”
What the heck do I do with this now?
Depth of CSS
Some of these things are • Experimental technology • In
working draft • In initial definition
Grid Layout Hype
P pointer-events “…specifies under what circumstances a particular graphic
element can become the target of mouse events.”
None
None
A Challenge
None
Thank you.