A collection of interesting things that are showing up in CSS specifications.

1. Next-level CSS
@rachelandrew #ffconf

2. Box Alignment level 3
Lining things up with

3. This is the vertical-
centering module.

4. .box {
display: flex;
align-items: center;
justify-content: center;
}
<div class="box">
<img alt="balloon" src="square-
balloon.jpg">
</div>
Flexbox
Centre the content of .box.

5. http://codepen.io/rachelandrew/pen/XKaZWm

6. http://codepen.io/rachelandrew/pen/RavbmN

7. .wrapper {
display: flex;
}
.wrapper li {
min-width: 1%;
flex: 1 0 25%;
}
.wrapper li:nth-child(2) {
align-self: center;
}
.wrapper li:nth-child(3) {
align-self: flex-start;
}
.wrapper li:nth-child(4) {
align-self: flex-end;
}
Flexbox
Aligning items within the flex
container

8. Box Alignment defines how
these properties work in
other layout methods.

9. The box alignment properties in CSS are a set of 6 properties
that control alignment of boxes within other boxes.
CSS BOX ALIGNMENT LEVEL 3
https://drafts.csswg.org/css-align/

10. CSS BOX ALIGNMENT LEVEL 3
▸ justify-content
▸ align-content
▸ justify-self
▸ align-self
▸ justify-items
▸ align-items

11. CSS Grid Layout
A proper layout system with

12. .wrapper {
display: grid;
grid-template-columns: repeat(4, 1fr);
}
.wrapper li {
min-width: 1%;
}
.wrapper li:nth-child(2) {
align-self: center;
}
.wrapper li:nth-child(3) {
align-self: start;
}
.wrapper li:nth-child(4) {
align-self: end;
}
CSS Grid Layout
Aligning grid items with the Box
Alignment properties.

13. http://codepen.io/rachelandrew/pen/jqdNoL

14. “Unlike Flexbox, however, which is single-axis–oriented, Grid
Layout is optimized for 2-dimensional layouts: those in which
alignment of content is desired in both dimensions.”
CSS GRID LAYOUT
https://drafts.csswg.org/css-grid/

15. .cards {
display:grid;
grid-template-columns: 1fr 1fr 1fr;
grid-gap: 10px;
}
CSS Grid Layout
Defining a 3 column grid

16. http://codepen.io/rachelandrew/pen/qqdGOa

17. .cards {
display:flex;
flex-wrap: wrap;
}
.card {
flex: 1 1 250px;
margin: 5px;
}
Flexbox
Flexbox can wrap flex items onto
multiple rows.
A new row becomes a new flex
container for the purposes of
distributing space.

18. http://codepen.io/rachelandrew/pen/VjzrgG

19. .cards {
display:grid;
grid-template-columns:
repeat(auto-fill, minmax(200px,1fr));
grid-gap: 10px;
}
CSS Grid Layout
Create as many columns as will fit
into the container with a minimum
width of 200px, and a maximum of
1fr.

20. minmax()

23. http://codepen.io/rachelandrew/pen/QKwvxJ

24. .home-hero {
display: grid;
grid-gap: 1px;
grid-auto-rows: minmax(150px,
auto);
}
minmax()
Rows should be a minimum of 150px
and a maximum of auto

25. CSS Grid auto-placement

26. <ul class="colors">
<li style="background-
color:#FFFFFF;color:black"
class="white">FFF FFF
</li>
<li style="background-
color:#CCCCCC;color:black">CCC CCC
</li>
<li style="background-
color:#999999;color:black"
class="span3">999 999
</li>
</ul>
Grid auto-placement
I have a list with all ye olde web safe
colours in it.

27. .colors {
display: grid;
grid-template-columns:
repeat(auto-fill,minmax(80px, 1fr));
grid-gap: 2px;
grid-auto-rows: minmax(80px, auto);
}
Grid auto-placement
I auto-fill columns and rows with
minmax()

28. http://codepen.io/rachelandrew/pen/LRWPNp/

29. .white {
grid-column: 1 / -1;
grid-row: 3;
}
.black {
grid-column: 1 / -1;
grid-row: 6;
}
.span2 {
grid-column-end: span 2;
grid-row-end: span 2;
}
.span3 {
grid-column-end: span 3;
grid-row-end: span 3;
}
.tall4 {
grid-row-end: span 4;
}
Grid auto-placement
Adding classes to some elements, by
setting the value of grid-column-end
and grid-row-end to span.

31. .colors {
display: grid;
grid-template-columns:
repeat(auto-fill,minmax(80px, 1fr));
grid-gap: 2px;
grid-auto-rows: minmax(80px, auto);
grid-auto-flow: dense;
}
Grid auto-placement
grid-auto-flow with a value of dense

33. http://gridbyexample.com/browsers/

34. display: contents
Vanishing boxes with

35. The element itself does not generate any boxes, but its children
and pseudo-elements still generate boxes as normal. For the
purposes of box generation and layout, the element must be
treated as if it had been replaced with its children and pseudo-
elements in the document tree.
DISPLAY: CONTENTS
https://drafts.csswg.org/css-display/#box-generation

36. allow indirect children to
become flex or grid items

37. <div class="wrapper">
<h1></h1>
<p></p>
<blockquote class="inset"></blockquote>
<p></p>
<ul class="images">
<li></li>
<li></li>
</ul>
<p></p>
</div>
display: contents
All elements are direct children of
‘wrapper’ except for the li elements.

38. .wrapper {
max-width: 700px;
margin: 40px auto;
display: grid;
grid-column-gap: 30px;
grid-template-columns:1fr 1fr;
}
.wrapper h1, .wrapper p {
grid-column: 1 / -1;
}
.inset {
grid-column: 1 ;
font: 1.4em/1.3 'Lora', serif;
padding: 0;
margin: 0;
}
.inset + p {
grid-column: 2;
}
display: contents
A two column grid. The h1, p and
blockquote with a class of inset are
all direct children.

39. http://codepen.io/rachelandrew/pen/gLborW

40. .images {
display: contents;
}
display: contents
The ul has a class of images. By
applying display: contents the ul is
removed and the li elements become
direct children.

41. http://codepen.io/rachelandrew/pen/gLborW

42. https://www.chromestatus.com/feature/5663606012116992

43. CSS Shapes
Getting curvy with

44. CSS Shapes describe geometric shapes for use in CSS. For Level
1, CSS Shapes can be applied to floats. A circle shape on a float
will cause inline content to wrap around the circle shape
instead of the float’s bounding box.
CSS SHAPES
https://drafts.csswg.org/css-shapes/

45. .balloon {
float: left;
width: 429px;
shape-outside: circle(50%);
}
<div class="box">
<img class="balloon" src="round-
balloon.png" alt="balloon">
<p>...</p>
</div>
CSS Shapes
A simple shape using the
shape-outside property

46. http://codepen.io/rachelandrew/pen/KrvyQq

47. .box::before {
content: "";
display: block;
float: left;
width: 429px;
height: 409px;
shape-outside: circle(50%);
}
CSS Shapes
Floating generated content to create
a shape

48. http://codepen.io/rachelandrew/pen/mErqxy

49. .balloon {
float: right;
width: 640px;
height: 427px;
shape-outside: ellipse(33% 50% at
460px);
-webkit-clip-path: ellipse(28% 50% at
460px);
clip-path: ellipse(28% 50% at 460px);
}
CSS Shapes
Using clip-path to cut away part of an
image

50. http://codepen.io/rachelandrew/pen/vKJmXR

51. http://caniuse.com/#feat=css-shapes

52. Feature Queries
Can I Use this with

53. The ‘@supports’ rule is a conditional group rule whose
condition tests whether the user agent supports CSS
property:value pairs.
FEATURE QUERIES
https://www.w3.org/TR/css3-conditional/#at-supports

54. http://caniuse.com/#feat=css-featurequeries

55. Anything new in CSS you
can use feature queries to
detect support.

56. @supports (display: grid) {
.has-grid {
/* CSS for grid browsers here */
}
}
Feature Queries
Checking for support of Grid Layout

57. @supports ((display: grid) and (shape-
outside: circle())) {
.has-grid-shapes {
/* CSS for these excellent browsers
here */
}
}
Feature Queries
Test for more than one thing

58. Using Feature Queries
▸ Write CSS for browsers without support
▸ Override those properties inside the feature queries
▸ See https://hacks.mozilla.org/2016/08/using-feature-queries-in-css/

59. .balloon {
border: 1px solid #999;
padding: 2px;
}
@supports ((shape-outside: ellipse()) and
((clip-path: ellipse()) or (-webkit-clip-
path:ellipse()))) {
.balloon {
border: none;
padding: 0;
float: right;
width: 640px;
min-width: 640px;
height: 427px;
shape-outside: ellipse(33% 50% at 460px);
-webkit-clip-path: ellipse(28% 50% at
460px);
clip-path: ellipse(28% 50% at 460px);
}
}
Feature Queries
Write CSS for browsers without
support, override that and add new
CSS inside the feature query.

60. http://codepen.io/rachelandrew/pen/vKJmXR

61. http://codepen.io/rachelandrew/pen/vKJmXR

62. Websites that enhance
themselves as the platform
improves.

63. Initial Letter
Fancy introductions with

64. Large, decorative letters have been used to start new sections
of text since before the invention of printing. In fact, their use
predates lowercase letters entirely.
This [initial-letter] property specifies styling for dropped, raised,
and sunken initial letters.
INITIAL LETTER
https://drafts.csswg.org/css-inline/#initial-letter-styling

65. h1+p::first-letter {
initial-letter: 4 3;
}
Initial Letter
Make the initial letter four lines tall,
one line above the content and 3 into
the content.

66. http://codepen.io/rachelandrew/full/WobvQq/

67. http://codepen.io/rachelandrew/full/WobvQq/

68. Currently Safari 9+ only.

69. h1+p::first-letter {
font-weight: bold;
initial-letter: 7 ;
background-color: rgb(114,110,151);
padding: 2em .5em;
margin: 0 5px 0 0;
color: #fff;
border-radius: 50% ;
float: left;
shape-outside: margin-box;
}
Initial Letter
Adding additional styling to the
initial letter.

70. http://codepen.io/rachelandrew/pen/LbEpPX

71. @supports (initial-letter: 3) or (-
webkit-initial-letter: 3) {
h1+p::first-letter {
font-weight: bold;
initial-letter: 7 ;
background-color: rgb(114,110,151);
padding: 2em .5em;
margin: 0 5px 0 0;
color: #fff;
border-radius: 50% ;
float: left;
shape-outside: margin-box;
}
}
Initial Letter
Using feature queries to test for
support before adding rules that
style the first letter.

72. http://codepen.io/rachelandrew/pen/LbEpPX

73. Writing modes
Upside down and back to front with

74. http://codepen.io/rachelandrew/pen/LbVQNW

75. .wrapper {
display: grid;
grid-template-columns: auto 1fr;
grid-gap: 40px;
}
h1 {
writing-mode: vertical-rl;
transform: rotate(180deg);
text-align: right;
grid-column: 1;
align-self: start;
justify-self: start;
}
Writing Modes
Using vertical-rl then flipping the text
with a transform.

76. http://codepen.io/rachelandrew/pen/LbVQNW

77. http://caniuse.com/#feat=css-writing-mode

78. Custom properties
Variables in CSS with

79. This module introduces a family of custom author-defined
properties known collectively as custom properties, which allow
an author to assign arbitrary values to a property with an
author-chosen name, and the var() function, which allow an
author to then use those values in other properties elsewhere in
the document.
CSS CUSTOM PROPERTIES (CSS VARIABLES)
https://drafts.csswg.org/css-variables/

80. :root {
--primary: blue;
--secondary: orange;
}
h1 {
color: var(--primary);
}
Custom Properties
Define variables then use them in
CSS

81. :root {
--primary: blue;
--secondary: orange;
}
@supports (--primary: blue) {
h1 {
color: var(--primary);
}
h2 {
color: var(--secondary);
}
}
Custom Properties
Can be tested for using feature
queries

82. http://codepen.io/rachelandrew/pen/mErpZA

83. http://caniuse.com/#feat=css-variables

84. calc()
Adding things up with

85. Basic mathematics in CSS

86. <div class="wrapper">
<div class="box box1">
<p>…</p>
<div>height is defined by the flex
container.</div>
</div>
<div class="box box2">
<div>height is 140px</div>
</div>
<div class="box box3">
<div>height is 14em</div>
</div>
</div>
calc()
Three boxes, each with a div nested
inside.

87. .box2 {
height: 140px;
}
.box3 {
height: 14em;
transition: height 0.5s ease;
}
.box3:hover {
height: 30em;
}
calc()
Two of the outer boxes have a height,
box1 is the height of the content
inside.
Box3 will grow on hover.

88. .box > div {
color: #fff;
border-radius: 5px;
position: absolute;
bottom: 20px;
right: 20px;
width: 30%;
height: calc(50% - 20px);
}
calc()
In the CSS for the inner box, we
calculate the height as 50% - 20px.

89. http://codepen.io/rachelandrew/full/VmYYqM/

90. http://caniuse.com/#feat=calc

91. position: sticky
Staying put with

92. A stickily positioned box is positioned similarly to a relatively
positioned box, but the offset is computed with reference to
the nearest ancestor with a scrolling box, or the viewport if no
ancestor has a scrolling box.
POSITION: STICKY
https://drafts.csswg.org/css-position/#sticky-pos

93. <dl class="authors">
<dt>A</dt>
<dd>John Allsopp</dd>
<dd>Rachel Andrew</dd>
<dt>B</dt>
<dd>. . .</dd>
</dl>
position: sticky
A dl with dt elements followed by
multiple dd elements.

94. .authors dt {
position: sticky;
top: 0;
}
position: sticky
Applying position: sticky to the dt

95. http://codepen.io/rachelandrew/pen/NbPamG

96. http://caniuse.com/#feat=css-sticky

97. Scroll snapping
Snap to it with

98. https://drafts.csswg.org/css-scroll-snap-1/

99. http://caniuse.com/#feat=css-snappoints

100. .gallery {
scroll-snap-type: mandatory;
scroll-snap-destination: 0 100% ;
scroll-snap-points-x: repeat(100%);
}
Scroll Snapping
Current Firefox implementation -
spec has since changed!

101. http://codepen.io/rachelandrew/pen/NbPGYg

102. .gallery {
scroll-snap-type: mandatory;
scroll-snap-destination: 0 100% ;
scroll-snap-points-y: repeat(100%);
}
Scroll Snapping
Current Firefox implementation -
spec has since changed!

103. http://codepen.io/rachelandrew/pen/xRbXqr

104. Getting our hands on all
the new shiny

105. Tell browser vendors you
want these features

106. https://developer.microsoft.com/en-us/microsoft-edge/platform/status/shapes/?q=shapes

107. Please comment on
emerging specifications

108. https://github.com/w3c/csswg-drafts/issues

109. Thank you
https://cssgrid.me/ffconf