Double-Colon for Pseudo-Elements
To differentiate between pseudo-elements and pseudo-classes, in CSS3 all pseudo-elements have a double-colon syntax. So instead of: :before, you do ::before.
All browsers are going to support the single-colon syntax, pretty much indefinitely, to abide by good design principles.
So that means we won’t be using the double-colon syntax until all browsers that don’t support it (including IE8, the current browser leader) are completely gone — which might not be for at least 2 or 3 years, and probably more.
All browsers are going to support the single-colon syntax, pretty much indefinitely, to abide by good design principles.
So that means we won’t be using the double-colon syntax until all browsers that don’t support it (including IE8, the current browser leader) are completely gone — which might not be for at least 2 or 3 years, and probably more.
( :root ) in css
The :root selector allow you to target the highest-level 'Parent' element in the dom, or document.
We can take advantage of being able to apply CSS to the
<html> element to skip the wrapper div and keep our markup clean!Browser Support for CSS3 Selectors
The Status of the ::selection Pseudo-element?
HTML5 Boilerplate put the
::selection pseudo-element on the map, so to speak, most CSS developers now a days have been including this selector as part of their universal styles.HTML5 Element Index
Head Part
- Doctype
- Title
- Base
- Link
- Meta
- Style
- Script
- Noscript
Section
- body
- article
- nav
- aside
- section
- header
- footer
- h1-h6
- main
- address
Grouping
- p
- hr
- pre
- blockquote
- ol
- ul
- li
- dl, dt, dd
- figure
- figcaption
- div
Tables
- table
- caption
- thread
- tbody
- tfoot
- tr, th, td
- col, colgroup
Form
- form
- fieldset
- legend
- label
- input
- button
- select
- datalist
- optgroup, option
- textarea
Form 2 HTML5
- keygen
- output
- progress
- meter
- detail
- summary
- command
- menu
Embedded
- img
- iframe
- embed
- object
- param
- video
- audio
- source
- canvas
- track
- map
- area
Text-level
- a
- em
- strong
- i, b
- u
- a
- small
- abbr
- q
- site
- dfn
- sub, sup
Text-level 2 HTML5
- time
- code
- kdb
- samp
- var
- mark
- bdi
- bdo
- ruby, rt, rp
- span
- br
- wbr
