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The ABCs of CSS You've Likely Never Used
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Alicia Sedlock
August 08, 2017
Technology
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The ABCs of CSS You've Likely Never Used
That Conference 2017
Alicia Sedlock
August 08, 2017
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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.