This is a quick reference list of CSS functions and how they can be used to modify an element’s properties.

• CSS – attr() Function
  The attr() function returns the value of an attribute of the selected element, and is sometimes used to show the value of the href attribute after a link.
• CSS – calc() Function
  The calc() function performs a mathematical calculation to be used as the property value.
• CSS – conic-gradient() Function
  The conic-gradient() function sets a conic gradient as the background image with at least two color transitions rotated around a center point.
• CSS – counter() Function
  The counter() function returns the current value of the named counter as a string.
• CSS – cubic-bezier() Function
  The cubic-bezier() function describes a curve that is defined by four points P0 (starting point/state), P1, P2, and P3 (ending point/state).
• CSS – hsl() Function
  The HSL color value is specified with the hsl() function, which has the following syntax: hsl(hue, saturation, lightness).
• CSS – max() Function
  The max() function uses the largest value, from a comma-separated list of values, as the property value.
• CSS – hsla() Function
  The HSLA color value is specified with the hsla() function, which has the following syntax: hsla(hue, saturation, lightness, alpha).
• CSS – min() Function
  The min() function uses the smallest value, from a comma-separated list of values, as the property value.
• CSS – linear-gradient() Function
  The linear-gradient() function sets a linear gradient as the background image.
• CSS – radial-gradient() Function
  The radial-gradient() function sets a radial gradient as the background image.
• CSS – repeating-linear-gradient Function
  The repeating-linear-gradient() function is used to repeat linear gradients.
• CSS – repeating-conic-gradient Function
  The repeating-conic-gradient() function is used to repeat conic gradients.
• CSS – rgb() Function
  An RGB color value is specified with the rgb() function, which has the following syntax: rgb(red, green, blue).
• CSS – repeating-radial-gradient Function
  The repeating-radial-gradient() function is used to repeat radial gradients.
• CSS – rgba() Function
  An RGBA color value is specified with the rgba() function, which has the following syntax: rgba(red, green, blue, alpha).
• CSS – var() Function
  The var() function is used to create a CSS variable and insert the value into a property.