Style Declarations

Tomasz Bogusz

A given HTML element is styled by CSS with style declarations.

A CSS style declaration is a block of code built with property/value pairs consisting of properties, colons, values and ending semicolons. The ending semicolon is optional for the last property/value pair.

An inline CSS style declaration must not be confined within any brackets.

Internal and external CSS style declarations must be confined within curly brackets and preceded by a selector.

p {
  font-size: 24px;
  color: red
}

The name of properties are strictly defined by CSS.

The CSS value data types are also strictly imposed by CSS. The value data types include:

  • keywords (e.g. inherit, blue),

  • integers and/or floats with units (e.g. 42px, 23%),

  • hexadecimals, RGBA, HSL, HSLA for colors.

CSS style declaration can define among others the following features of an element:

  • positioning (x-axis, y-axis and z-axis),

  • size,

  • shape,

  • borders,

  • background color and/or picture,

  • text alignment, and

  • font family and color.

When style declarations have the same specificity associated the last defined style declaration is applied.