CSS Radial Gradients

Style pages using radial gradients

Apply radial gradients to backgrounds on your website. Modern browsers that support CSS3 will be able to view radial gradients. Gradients must have a minimum of two colours.

Radial gradients can also be created using and SVG file and embedded into HTML using tags Modern browsers that support SVG enable cross-browser compatibility.

In this tutorial, only three-colour gradients will be used .

    Tools are required:

  • Text editor for creating and modifying the page hits counter files.
  • SVG editor for creating gradient shapes that may be embedded.
  • Web server.
  • CSS.
  • HTML.
  • Knowledge of the files to be served.

Using Inkscape to create an SVG file

    Run Inkscape:

  • File -> Document Properties -> Custom size.
  • Create image 400 x 50px.
  • Create Rectangles and squares Tool -> create rectangle.
  • Create and edit gradients Tool -> Create radial gradient.
  • Edit -> Add stop.
  • Change stop 1 Colour to Yellow = FFFF00.
  • Change stop 2 Colour to Black = FFFFFF.
  • Change stop 3 Colour to Red = FF0000.
  • Save as Ojambo_RadialGradient.svg.
Image Missing
Inkscape Canvas

Index.html file

<!--
        index.html

        Copyright 2011 Edward <http://ojambo.com/contact>

-->

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

<head>
	<title>Ojambo.com Radial Gradients Tutorial</title>
	<meta http-equiv="content-type" content="text/html;charset=utf-8" />
	<style type="text/css"> 
		div#multiple-colours-radial {
			height:50px;
			
			/* Non-CSS3 browsers */
			background: #999; 

			/* W3C Specification */
			background: radial-gradient([<bg-position>,]? [[<shape> || <size>] | [<length> | <percentage>]{2}	,]? <color-stop>[, <color-stop>]+);

			/* Webkit browsers */
			background: -webkit-gradient(radial, center center, 0, center center, 50, color-stop(0, yellow), color-stop(0.45, #000), color-stop(1, red));

			/* Mozilla browsers */
			background: -moz-radial-gradient(center, yellow 0%, #000 25%, red 80%);
		}
	</style>
</head>

<body>
	<h1>Ojambo.com Radial Gradients Tutorial</h1>
	<p>Multiple colour stops radial</p>
	<div id="multiple-colours-radial"></div>
	<p>For Modern Broswers supporting SVG</p>
<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:xlink="http://www.w3.org/1999/xlink"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   width="400"
   height="50"
   id="svg2"
   version="1.1"
   inkscape:version="0.48.0 r9654"
   sodipodi:docname="New document 1">
  <defs
     id="defs4">
    <linearGradient
       id="linearGradient3755">
      <stop
         style="stop-color:#ffff00;stop-opacity:1"
         offset="0"
         id="stop3757" />
      <stop
         id="stop3763"
         offset="0.51057482"
         style="stop-color:#000000;stop-opacity:1" />
      <stop
         style="stop-color:#ff0000;stop-opacity:1"
         offset="1"
         id="stop3759" />
    </linearGradient>
    <radialGradient
       inkscape:collect="always"
       xlink:href="#linearGradient3755"
       id="radialGradient3761"
       cx="213.61472"
       cy="-169.97751"
       fx="213.61472"
       fy="-169.97751"
       r="200"
       gradientTransform="matrix(-0.00261332,0.14398508,-0.52061283,-0.00944903,55.993809,-13.547861)"
       gradientUnits="userSpaceOnUse" />
  </defs>
  <sodipodi:namedview
     id="base"
     pagecolor="#ffffff"
     bordercolor="#666666"
     borderopacity="1.0"
     inkscape:pageopacity="0.0"
     inkscape:pageshadow="2"
     inkscape:zoom="1.6675"
     inkscape:cx="200"
     inkscape:cy="25"
     inkscape:document-units="px"
     inkscape:current-layer="layer1"
     showgrid="false"
     inkscape:window-width="791"
     inkscape:window-height="770"
     inkscape:window-x="0"
     inkscape:window-y="14"
     inkscape:window-maximized="0" />
  <metadata
     id="metadata7">
    <rdf:RDF>
      <cc:Work
         rdf:about="">
        <dc:format>image/svg+xml</dc:format>
        <dc:type
           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
        <dc:title></dc:title>
      </cc:Work>
    </rdf:RDF>
  </metadata>
  <g
     inkscape:label="Layer 1"
     inkscape:groupmode="layer"
     id="layer1"
     transform="translate(0,-1002.3622)">
    <rect
       style="color:#000000;fill:url(#radialGradient3761);fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:15;marker:none;visibility:visible;display:inline;overflow:visible;enable-background:accumulate"
       id="rect2985"
       width="400"
       height="50"
       x="1.7991004"
       y="0.22488755"
       transform="translate(0,1002.3622)" />
  </g>
</svg>	
</body>

</html>

To generate a three colour radial gradient from center, a container called “multiple-colours-radial” is used. The height of 50px and the default background for non-CSS3 browsers are specified. For future references, the W3C specification is included. Currently only Webkit and Mozilla support the radial gradients using proprietary formats -webkit-gradient and -moz-radial-gradient respectively. For webkit browsers, definations are radial, background position, shape and size, and the colours are defined with “from” and “to”. For mozilla browsers, center indicates the position, and the first colour is defined automatically.

For modern browsers that support the SVG specifications, gradients can be created and directly embedded as text but will show up as objects. In this tutorial, Inkscape is used to create rectangular shapes which are saved as SVG files. The SVG files can be opened in any text editor and them simply pasted into HTML.

Example:

Multiple colour stops radial

For Modern Broswers supporting SVG

image/svg+xml

    Recommendations:

  1. Put the styles is a separate css file.
  2. Please note, that this works only for mozilla and webkit browsers.
  3. Other browsers can display gradients as images if they support SVG.

Tags: , , , , , , , ,

This entry was posted on Saturday, January 15th, 2011 at 4:17 am and is filed under Tips & Tricks. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

5 Responses to “CSS Radial Gradients”

  1. Ojambo CSS Radial Gradients Video 0010 Says:

    June 8th, 2011 at 8:43 am

    […] Video for the ojambo.com css radial gradients article. Part One of […]

  2. Bolivar Says:

    December 8th, 2012 at 11:38 am

    hello, i need help with the css export tool on inkscape i would like to know why i can’t export my slides as css

    this is what is shown

    Traceback (most recent call last):

    Traceback (most recent call last):

    File “webslicer_export.py”, line 437, in

    e.affect()

    File “C:\Program Files\Inkscape\share\extensions\inkex.py”, line 215, in affect

    self.effect()

    File “webslicer_export.py”, line 119, in effect

    error = self.validate_inputs()

    File “webslicer_export.py”, line 75, in validate_inputs

    self.unique_html_id( self.get_slicer_layer() )

    File “webslicer_export.py”, line 96, in unique_html_id

    for child in el.getchildren():

    AttributeError: ‘NoneType’ object has no attribute ‘getchildren’

  3. Liliz Says:

    March 30th, 2013 at 12:35 pm

    Hi, I have the same problem on Inkscape 0.48 on Ubuntu 12.10.

    The Web -> Slicer command gives an attribute error on webslicer_export.py

    ‘NoneType’ object has no attribute ‘getchildren’

    It would be good to have some help on this feature (maybe we should also post a bug on the inkscape project?)

  4. Edward Says:

    March 31st, 2013 at 1:12 am

    For instructions on reporting Inkscape bugs, please visit their site at http://inkscape.org/report_bugs.php. You can also use SVG file directly with modern browsers.

  5. Edward Says:

    March 31st, 2013 at 1:17 am

    I apologize for the late reply. You can use SVG directly in HTML or import as an image in CSS. I will create a tutorial as part of a game later using an SVG file as the background CSS.

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