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CSS backgrounds and borders

{{CSSRef}} 

The CSS backgrounds and borders module provides properties for adding backgrounds, borders, rounded corners, and box shadows to elements.

You can add different types of border styles, including borders made of images of any image type, from raster images to CSS gradients. Borders can be square or rounded, and a different radius can be set for each corner. Elements can be rounded whether or not they have a visible border.

Box shadows include inset and outset shadow, single or multiple shadows, and solid or allowed to fade to transparent. An outer box-shadow casts a shadow as if the border-box of the element were opaque. An inner box-shadow casts a shadow as if everything outside the padding edge were opaque. The shadow can be solid or include a spread distance with the shadow color transitioning to transparent.

The properties in this module also let you define whether cells inside a {{HTMLElement("table")}}  should have shared or separate borders.

Backgrounds, borders, and box shadows in action

This sample of borders, backgrounds, and box shadows consists of centered background images made of linear and radial gradients. A series of box shadows make the border appear to “pop”. The element on the left has a border image set. The element on the right has a rounded dotted border.

<article>
  <div></div>
  <div></div>
</article>

article {
  display: flex;
  gap: 10px;
}
div {
  color: #58ade3;
  height: 320px;
  width: 240px;
  padding: 20px;
  margin: 10px;
  border: dotted 15px; /* defaults to `currentcolor` */
  border-radius: 100px 0;
  background-image:
    radial-gradient(
      circle,
      transparent 60%,
      currentcolor 60% 70%,
      transparent 70%
    ),
    linear-gradient(45deg, currentcolor, white),
    linear-gradient(transparent, transparent);
  /* the third transparent background image was added to provide space for the background color to show through */
  background-color: currentcolor;
  background-position: center;
  background-size:
    60px 60px,
    120px 120px;
  background-clip: content-box, content-box, padding-box;
  box-shadow:
    inset 5px 5px 5px rgb(0 0 0 / 0.4),
    inset -5px -5px 5px rgb(0 0 0 / 0.4),
    5px 5px 5px rgb(0 0 0 / 0.4),
    -5px -5px 5px rgb(0 0 0 / 0.4);
}
div:first-of-type {
  border-radius: 0;
  border-image-source: repeating-conic-gradient(
    from 3deg at 25% 25%,
    currentColor 0 3deg,
    transparent 3deg 6deg
  );
  border-image-slice: 30;
}

{{EmbedLiveSample("backgrounds", "", "450px")}} 

The background images are defined with {{cssxref("background-image")}} . The images are centered with {{cssxref("background-position")}} . Different values of the {{cssxref("background-clip")}}  property for the multiple background images are used to make the background images stay within the content box. The background color gets clipped to the padding box preventing the background from appearing through the transparent sections for the {{cssxref("border-image")}}  and the {{cssxref("border-style", "dotted")}}  {{cssxref("border")}} . The rounded corners in the element on the right are created using the {{cssxref("border-radius")}}  property. A single {{cssxref("box-shadow")}}  declaration is used to set all the shadows, both inset and outset.

Click “Play” in the example above to see or edit the code for the animation in the MDN Playground.

Reference

Properties

[!NOTE] The CSS Backgrounds Module Level 4 introduces the background-position-block, background-position-inline, background-repeat-block, background-repeat-inline, background-repeat-x, background-repeat-y, and background-tbd properties. These have not yet been implemented.

Data types

Guides

Specifications

{{Specifications}} 

See also

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