SVG and CSS

This page illustrates the application of CSS to the specialized language for creating graphics: SVG.

You create a simple demonstration that runs in your SVG-enabled browser.

This is the 2nd section of Part II of the CSS tutorial.
Previous section: JavaScript
Next section: XML data

Information: SVG

SVG (Scalable Vector Graphics) is an XML-based language for creating graphics.

It can be used for static images, and also for animations and user interfaces.

Like other XML-based languages, SVG supports CSS stylesheets so that you can separate the style of a graphic from its content.

Also, stylesheets that you use with other document markup languages can specify the URL of an SVG graphic where an image is required. For example, a stylesheet that you use with an HTML document can specify the URL of an SVG graphic in the value of a background property.

Action: An SVG demonstration

Make a new SVG document as a plain text file, doc8.svg. Copy and paste the content from here, making sure that you scroll to get all of it:

<?xml version="1.0" standalone="no"?>

<?xml-stylesheet type="text/css" href="style8.css"?>

<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
  "https://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

<svg width="600px" height="600px" viewBox="-300 -300 600 600"
  xmlns="https://www.w3.org/2000/svg" version="1.1"
  xmlns:xlink="https://www.w3.org/1999/xlink">

<title>SVG demonstration</title>
<desc>Mozilla CSS Getting Started - SVG demonstration</desc>

<defs>
  <g id="segment" class="segment">
    <path class="segment-fill" d="M0,0 v-200 a40,40 0 0,0 -62,10 z"/>
    <path class="segment-edge" d="M0,-200 a40,40 0 0,0 -62,10"/>
    </g>
  <g id="quadrant">
    <use xlink:href="#segment"/>
    <use xlink:href="#segment" transform="rotate(18)"/>
    <use xlink:href="#segment" transform="rotate(36)"/>
    <use xlink:href="#segment" transform="rotate(54)"/>
    <use xlink:href="#segment" transform="rotate(72)"/>
    </g>
  <g id="petals">
    <use xlink:href="#quadrant"/>
    <use xlink:href="#quadrant" transform="rotate(90)"/>
    <use xlink:href="#quadrant" transform="rotate(180)"/>
    <use xlink:href="#quadrant" transform="rotate(270)"/>
    </g>
  <radialGradient id="fade" cx="0" cy="0" r="200"
      gradientUnits="userSpaceOnUse">
    <stop id="fade-stop-1" offset="33%"/>
    <stop id="fade-stop-2" offset="95%"/>
    </radialGradient>
  </defs>

<text id="heading" x="-280" y="-270">
  SVG demonstration</text>
<text  id="caption" x="-280" y="-250">
  Move your mouse pointer over the flower.</text>

<g id="flower">
  <circle id="overlay" cx="0" cy="0" r="200"
    stroke="none" fill="url(#fade)"/>
  <use id="outer-petals" xlink:href="#petals"/>
  <use id="inner-petals" xlink:href="#petals"
    transform="rotate(9) scale(0.33)"/>
  </g>

</svg>

Make a new CSS file, style8.css. Copy and paste the content from here, making sure that you scroll to get all of it:

/*** SVG demonstration ***/

/* page */
svg {
  background-color: beige;
  }

#heading {
  font-size: 24px;
  font-weight: bold;
  }

#caption {
  font-size: 12px;
  }

/* flower */
#flower:hover {
  cursor: crosshair;
  }

/* gradient */
#fade-stop-1 {
  stop-color: blue;
  }

#fade-stop-2 {
  stop-color: white;
  }

/* outer petals */
#outer-petals {
  opacity: .75;
  }

#outer-petals .segment-fill {
  fill: azure;
  stroke: lightsteelblue;
  stroke-width: 1;
  }

#outer-petals .segment-edge {
  fill: none;
  stroke: deepskyblue;
  stroke-width: 3;
  }

#outer-petals .segment:hover > .segment-fill {
  fill: plum;
  stroke: none;
  }

#outer-petals .segment:hover > .segment-edge {
  stroke: slateblue;
  }

/* inner petals */
#inner-petals .segment-fill {
  fill: yellow;
  stroke: yellowgreen;
  stroke-width: 1;
  }

#inner-petals .segment-edge {
  fill: none;
  stroke: yellowgreen;
  stroke-width: 9;
  }

#inner-petals .segment:hover > .segment-fill {
  fill: darkseagreen;
  stroke: none;
  }

#inner-petals .segment:hover > .segment-edge {
  stroke: green;
  }

Open the document in your SVG-enabled browser. Move your mouse pointer over the graphic.

This wiki does not support SVG in pages, so it is not possible to show the demonstration here. The graphic looks like this:

Notes about this demonstration:

• The SVG document links the stylesheet in the usual way.
• SVG has its own CSS properties and values. Some of them are similar to CSS properties for HTML.

See a solution to this challenge.

What next?

In this demonstration, your SVG-enabled browser already knows how to display SVG elements. The stylesheet only modifies the display in certain ways. This is also true for HTML and XUL documents. But you can use CSS for general-purpose XML documents, where there is no predefined way to display the elements. The next page demonstrates this: XML data