FToPx returns `f` as pixels.

Return true except for 0 or nil.

MaybeFloatToFloat is the same as MaybeFloat.V(), but handles nil values.

Return the percentage of the reference value, or the value unchanged.

"auto".

AutoF indicates a value specified as "auto", which will be resolved during layout.

"none".

The following properties are all background related, in the order expected by expandBackground.

the following properties are grouped by side, in the [bottom, left, right, top] order, so that, if side in an index (0, 1, 2 or 3), the property is a PBorderBottomColor + side * 5 DO NOT CHANGE the order, because.

percentage (%).

text-decoration-XXX.

min-XXX is at +2, max-XXX is a + 4.

means no unit, but a valid value.

Value in pixels of font-size for <absolute-size> keywords: 12pt (16px) for medium, and scaling factors given in CSS3 for others: http://www.w3.org/TR/css3-fonts/#font-size-prop.

Do not list shorthand properties here as we handle them before inheritance.

InitialValues stores the default values for the CSS properties.

How many CSS pixels is one <unit>? http://www.w3.org/TR/CSS21/syndata.html#length-units.

Not applicable to the print media.

http://www.w3.org/TR/css3-page/#size.

PropsFromNames maps CSS property names to internal enum tags.

http://www.w3.org/TR/CSS21/tables.html#model See also http://lists.w3.org/Archives/Public/www-style/2012Jun/0066.html Only non-inherited properties need to be included here.

CascadedProperty is the second form of a CSS input : var() calls have been resolved and the remaining raw properties have been checked.

Counters store a counter() or counters() attribute.

Dimension without unit is interpreted as float.

OptionalRanges is either 'auto' or a slice of ranges.

PropKey stores a CSS property name, supporting variables.

SFloatStrings is either a string or a list of (string, float) pairs.

Dimension or "auto" or "cover" or "contain".

SpecifiedAttributes stores the value of CSS properties as specified.

TextRatioCache stores the 1ex/font_size or 1ch/font_size ratios, for each font.

ValidatedProperty is the most general CSS input for a property.

ElementStyle defines a common interface to access style properties.

Might be an existing image or a gradient.

guard for possible content properties.

MaybeBool stores a tree state boolean : true, false or nil.

KnownProp efficiently encode a known CSS property.

Properties is the general container for validated, cascaded and computed properties.

---------------------- helpers types -----------------------------------.

Tag is a flag indicating special values, such as "none" or "auto".