freeCodeCamp/guide/english/css/box-shadow/index.md

title
Box Shadow

Box Shadow

The box-shadow property attaches one or more shadows around the frame of an element (can be inside). It's an option that gives you the power to easily design wonderful shadow effects. Box shadows are a great way to elevate the visuals of your web page.

A box shadow can be described with several properties including:

• X and Y offset from the element
• blur and spread radius
• color

Syntax:

  div {
    box-shadow: none | [inset? && [ <offset-x> <offset-y> <blur-radius>? <spread-radius>? <color>? ] ]#
    }

• inset (default: none)

If not specified, the shadow is assumed to be a drop shadow (as if the box were raised above the content). The presence of the inset keyword changes the shadow to one inside the frame.

• offset-x offset-y

These are two length values to set the shadow offset. specifies the horizontal distance. Negative values place the shadow to the left of the element. offset-y specifies the vertical distance. Negative values place the shadow above the element. See length for possible units.

• blur-radius (default: 0)

This is a third length value. The larger this value, the bigger the blur, so the shadow becomes bigger and lighter. Negative values are not allowed. If not specified, it will be 0 (the shadow's edge is sharp).

• spread-radius (default: 0)

This is a fourth value. Positive values will cause the shadow to expand and grow bigger, negative values will cause the shadow to shrink. If not specified, it will be 0 (the shadow will be the same size as the element).

• color

This value is used to set the color of the shadow, usually defined with hex #000000, rgba value rgba(55,89,88,0.8) or rgb value rgb(55,89,88).

Extended

To maximize compatibility, it is recommended that you declare box shadow properties for moz-appearance and webkit, this extends the normal syntax to:

   div{
      box-shadow: none | [inset? && [ <offset-x> <offset-y> <blur-radius>? <spread-radius>? <color>? ] ]#
      -moz-box-shadow: none | [inset? && [ <offset-x> <offset-y> <blur-radius>? <spread-radius>? <color>? ] ]#
      -webkit-box-shadow: none | [inset? && [ <offset-x> <offset-y> <blur-radius>? <spread-radius>? <color>? ] ]#
   }

However, this step can be ignored if it is creating confusion, as moz property and webkit property will only work in specific applications such as Firefox, and are not on a standards track.

Examples

Basic use

div {
  width: 200px;
  height: 50px;
  background-color: #333;
  box-shadow: 10px 10px 5px #ccc;
}

10px - offset-x 10px - offset-y 5px - blur #ccc - light gray color

It will display

Inside box shadow

div {
  width: 200px;
  height: 50px;
  background-color: #333;
  box-shadow: inset 10px 10px 5px #ccc;
}

It uses very similar code, but with inset value, which displays shadow inside the div element.

Multiple box shadows

div {
    width: 200px;
    height: 50px;
    background-color: #333;
    box-shadow: inset 10px 10px 5px #ccc, 10px 10px 5px #ccc;
}

You can combine the previous two pieces of box-shadows using a comma to get multiple box shadows on the same div

More Information

• Docs: MDN