CSS3

Agrega la propiedad opacity y las funciones hsl(), hsla(), rgba() and rgb() para crear los valores <color>. También define la palabra clave currentColor como un color válido.

Ahora el color transparente es un color real (gracias al soporte para el canal alpha) y es un alias para rgba(0,0,0,0.0) .

Deja obsoleto las keyworks del sistema de colores (system-color) las cuales ya no deberían ser usadas en ambientes de producción.

Agrega:

• Atributo substring selector de igualdad, E[attribute^="value"] , E[attribute$="value"] , E[attribute*="value"] .
• Nuevas pseudo-clases: :target, :enabled y :disabled, :checked, :indeterminate, :root, :nth-child y :nth-last-child, :nth-of-type y :nth-last-of-type, :last-child, :first-of-type y :last-of-type, :only-child y :only-of-type,:empty, y :not.
• Los Pseudo-elementos ahora son caracterizados por un par de dos puntos en vez de sólo uno: :after ahora es ::after, :before ahora es ::before, :first-letter ahora es ::first-letter, y :first-line ahora es ::first-line.
• El nuevo combinador general de hermanos (general sibling combinator) ( h1~pre ).

Añade soporte para los nombres de espacio XML (namespaces) definiendo la noción de nombre CSS cualificado (CSS qualified name), usando la sintaxis ' | ' y agregando la regla CSS @namespace.

Extiende los tipos anteriores de media ( print, screen, … ) a un lenguaje completo permitiendo queries sobre las capacidades de  media del dispositivo como only screen y color.

Los Media queries no sólo son usado en documentos CSS sino también en algunos atributos de elementos HTML, como el atributo media del elemento <link>.

Define formalmente la sintaxis del contenido del atributo global style de HTML.

Agrega:

• Soporte en fondos para cualquier tipo de <image> y no solo las uri() definidas.
• Soporte para multiples imágenes de fondo.
• Los valores background-repeat space y round, y para la sintaxis de dos-valores de esta propiedad CSS.
• El valor local de background-attachment.
• Las propiedades CSS de background-origin, background-size y background-clip.
• Soporte para border curvos con las propiedades CSS border-radius, border-top-left-radius, border-top-right-radius, border-bottom-left-radius, y border-bottom-right-radius.
• Soporte para el uso de una <image> como borde con las propiedades CSS border-image, border-image-source, border-image-slice, border-image-width, border-image-outset, y border-image-repeat.
• Soporte para sombras de elemento con la propiedad CSS box-shadow.

Se define el tipo de dato <image>.

Se extiende la sintaxis  de url() para dar soporte a cortes de imágenes usando media fragments.

Agregados:

• La unidad dppx al tipo de dato <resolution>.
• La función image() como una alternativa más flexible a  url() para definir una imagen desde una URL.
  Un riesgo : Dado el insuficiente soporte por los navegadores, la estandarización de la función image() debe ser postergada a la siguiente iteración de este módulo .
• Soporte para linear-gradient(), repeating-linear-gradient(), radial-gradient() and repeating-radial-gradient().
• La capacidad de definir cómo reemplazar el elemento que encaja en sus elementos, usando al propiedad CSS object-fit.
  Un riesgo : Dado el insuficiente soporte por los navegadores, la estandarización de  object-fit y propiedad debe ser posterga a la siguiente iteración de este módulo.
• La capacidad de sobreescribir la resolución y la orientacion de una imagen externa usando el CSS image-resolution y image-orientation .
  RIESGO : debido al bajo soporte de los navegadores, la estandarización de image-resolution y image-orientation podría posponerse para la próxima iteración

Makes initial and inherit keywords usable on any CSS property.

Formally defines the CSS data types of CSS 2.1, that were implicitely defined by their grammar token and some textual precisions.

Adds:

• Definition for new font-relative length units: rem and ch .
• Definition for viewport-relative length units: vw, vh, vmax, and vmin .
• Precision about the real size of the absolute length units, which are not really absolute, but defined in relation with the reference pixel .
• Definition for <angle>, <time>, <frequency>, <resolution>.
• Normative value to the definition of <color>, <image>, and <position>.
• Definition for the calc(), attr(), and toggle() functional notations.
  At risk: due to insufficient browser support, standardization of the calc(), attr(), and toggle() functional notations may be postponed to the next iteration of this module.

Extends:

• the CSS text-decoration property by making it a shorthand for the CSS text-decoration-line, text-decoration-color, and text-decoration-style properties. And adds the text-decoration-skip, and text-underline-position properties.

Adds:

• Support for East-Asian-script emphasis marks with the CSS text-emphasis, text-emphasis-style, text-emphasis-color, and text-emphasis-position properties.
• Support for script shadows with the CSS text-shadow property.

Precises:

• The paint order of the decorations.

At risk: due to insufficient browser support, standardization of the text-decoration-skip, line positioning rules and the ability to place both emphasis marks and ruby above the same base text may be postponed to the next iteration of this module.

Amends the CSS2.1 Font matching algorithm to be closer to what is really implemented.

Adds:

• Support for downloadable fonts via the CSS @font-face at-rule.
• The control of the contextual inter-glyph spacing via the CSS font-kerning property.
• The choice of language-specific glyphs via the CSS font-language-override property.
• The choice of glyphs with specific OpenType features via the CSS font-feature-settings property.
• The control of the aspect ratio to use when fallback fonts are selected via the CSS font-size-adjust property.
• The choice of alternative font faces using the CSS font-stretch, font-variant-alternates, font-variant-caps, font-variant-east-asian, font-variant-ligatures, font-variant-numeric, and font-variant-position properties. It also extends the related CSS font-variant shorthand property and introduces the @font-features-values at-rule.
• The control of the automatic generation of an oblique or bold face when none are found via the CSS font-synthesis property.

Adds:

• The ability to tweak the box model using the CSS box-sizing property.
  At risk: due to insufficient browser support, standardization of the padding-box value may be postponed to the next iteration of this module .
• Allow the styling of forms according their content using the CSS :indeterminate, :default, :valid, :invalid, :in-range, :out-of-range, :required, :optional, :read-only, and :read-write pseudo-classes and the ::value, ::choices, ::repeat-item, and ::repeat-index pseudo-elements.
  At risk: due to insufficient browser support, standardization of the pseudo-elements ::value, ::choices, ::repeat-item, and ::repeat-index may be postponed to the next iteration of this module .
• Support for icons, defined by the CSS icon property simultaneously with the new icon value of the CSS content property.
  At risk: due to insufficient browser support, standardization of the icon property and the icon value may be postponed to CSS4.
• Support for the CSS outline-offset property giving more control on the position of the outline.
• Support for the CSS resize property allowing Web authors to control if and how elements should be resized.
• Support for the CSS text-overflow property defining how text overflows, if needed.
  At risk: due to insufficient browser support, the 2-value syntax of this property as well as the support for <string> values may be postponed to the next iteration of this module .
• The ability to define the hotspot of a cursor as well as the new none, context-menu, cell, vertical-text, alias, copy, no-drop, not-allowed, nesw-resize, nwse-resize, col-resize, row-resize, all-scroll, zoom-in, zoom-out, extending the cursor property.
• The ability to specify the sequential navigation order (that is the tabbing order ) using the CSS nav-index, nav-up, nav-right, nav-left, nav-down properties.
  At risk: due to insufficient browser support, standardization of the navigation properties may be postponed to the next iteration of this module .
• The ability to control the usage of an IME editor, using the CSS ime-mode property.
  At risk: due to insufficient browser support, standardization of the ime-mode property may be postponed to the next iteration of this module .

Adds:

• the support of bi-dimensional transforms to be applied to any element using the CSS transform and transform-origin properties. The supported transforms are: matrix(), translate(), translateX(), translateY(), scale(), scaleX(), scaleY(), rotate(), skewX(), and skewY().
• the support of tri-dimensional transforms to be applied to any element by adding the CSS transform-style, perspective, perspective-origin, and backface-visibility properties and extended the transform property with the following transforms are: matrix 3d(), translate3d(), translateZ(),  scale3d(), scaleZ(), rotate3d(), rotateX() ,rotateY(), rotateZ(), and perspective().

Note: this specification is a merge of CSS 2D-Transforms, CSS 3D-Transforms and SVG transforms.

Adds:

• Support for defining the behavior of decorations, that is borders and background colors or images, when a box is breaked (at a page, column or line-break) with the CSS box-decoration-break property.

Extends:

• the CSS text-transform property with the value full-width.
• the CSS text-align property with the value start, end, start end, and match-parent for a better support of documents with multiple directionalities of text.
• the CSS text-align property with a <string> value to align on that character. This is useful to align number on the decimal point.
• the CSS word-spacing and letter-spacing properties with range constraints to control flexibility in justification.

Adds:

• Control on how whitespaces are displayed using the CSS text-space-collapse and tab-size properties.
• Control on line breaks and word boundaries using the CSS line-break, word-break, hyphens, text-wrap, overflow-wrap, and text-align-last properties.
• Control on how justification is happening, in order to support more type of scripts, using the CSS text-justify property.
• Control on edge effect using the CSS text-indent and hanging-punctuation properties.

Extends:

• the image() functional notation to describe the directionality of the image (rtl or ltr), allowing for bidi-sensitive images.
• the image-orientation property by adding the keyword from-image, allowing to follow EXIF data stored into images to be considered.

Adds:

• the image-set() functional notation to allow the definition to equivalent images at different resolution allowing for resolution-negotiated selection of images.
• the element() functional notation allowing the use of part of the page as image.
• the cross-fade() functional notation allowing to refer to intermediate images when transitioning between two images and defines the interpolation between two images.
• the conic-gradient() and repeating-conic-gradient() functional notation describing a new type of gradient.
• the image-rendering property that allow to define how resize of the object should be handled.