The SpryTabbedPanels.css file contains the rules that style the Tabbed Panels widget. You can edit these rules to style the tabbed panels’ look and feel. The names of the rules in the CSS file correspond directly to the names of the classes specified in the Tabbed Panels widget’s HTML code.

The default functionality for the behaviors classes at the end of the style sheet are defined in the SpryTabbedPanels.js JavaScript library file. You can change the default functionality by adding properties and values to the behavior rules in the style sheet.

The following is the CSS code for the SpryTabbedPanels.css file. The first half of the file contains styling rules for horizontal tabbed panels. The second half of the file contains styling rules for vertical tabbed panels.

/* Horizontal Tabbed Panels */
.TabbedPanels {
	margin: 0px;
	padding: 0px;
	clear: both;
	width: 100%; /* IE Hack to force proper layout when preceded by a paragraph. (hasLayout Bug)*/
}
.TabbedPanelsTabGroup {
	margin: 0px;
	padding: 0px;
}
.TabbedPanelsTab {
	position: relative;
	top: 1px;
	float: left;
	padding: 4px 10px;
	margin: 0px 1px 0px 0px;
	font: bold 0.7em sans-serif;
	background-color: #DDD;
	list-style: none;
	border-left: solid 1px #CCC;
	border-bottom: solid 1px #999;
	border-top: solid 1px #999;
	border-right: solid 1px #999;
	-moz-user-select: none;
	-khtml-user-select: none;
	cursor: pointer;
}
.TabbedPanelsTabHover {
	background-color: #CCC;
}
.TabbedPanelsTabSelected {
	background-color: #EEE;
	border-bottom: 1px solid #EEE;
}
.TabbedPanelsTab a {
	color: black;
	text-decoration: none;
}
.TabbedPanelsContentGroup {
	clear: both;
	border-left: solid 1px #CCC;
	border-bottom: solid 1px #CCC;
	border-top: solid 1px #999;
	border-right: solid 1px #999;
	background-color: #EEE;
}
.TabbedPanelsContent {
	padding: 4px;
}
.TabbedPanelsContentVisible {
}
/* Vertical Tabbed Panels */
.VTabbedPanels .TabbedPanelsTabGroup {
	float: left;
	width: 10em;
	height: 20em;
	background-color: #EEE;
	position: relative;
	border-top: solid 1px #999;
	border-right: solid 1px #999;
	border-left: solid 1px #CCC;
	border-bottom: solid 1px #CCC;
}
.VTabbedPanels .TabbedPanelsTab {
	float: none;
	margin: 0px;
	border-top: none;
	border-left: none;
	border-right: none;
}
.VTabbedPanels .TabbedPanelsTabSelected {
	background-color: #EEE;
	border-bottom: solid 1px #999;
}
.VTabbedPanels .TabbedPanelsContentGroup {
	clear: none;
	float: left;
	padding: 0px;
	width: 30em;
	height: 20em;
}

The SpryTabbedPanels.css file contains extensive comments, explaining the code and the purpose for certain rules. For further information, see the comments in the file.