MediaWiki:Common.css

/* CSS placed here will be applied to all skins */
/* Collapse Toggle container */

#collapse-pre-one .mw-collapsible-toggle{
 display: table;
 background-color: lightblue;
  color: black;
 border-collapse: collapse;
 width: 100%;
}

#collapse-pre-one .mw-collapsible-toggle-row{
 display: table-row;
}

/* Collapse Header should be on the left */
#collapse-pre-one .mw-collapsible-toggle .mw-collapsible-toggle-header{
 display: table-cell;
 vertical-align: middle;
 padding: 5px;
}

/* Collapse indicator image should be inline. align wherever you would like */
#collapse-pre-one .mw-collapsible-toggle .mw-collapsible-toggle-indicator{
 display: table-cell;
 vertical-align: middle;
 padding: 5px;
 text-align: right;
}

/* Collapse indicator image size should be something sane*/
#collapse-pre-one .mw-collapsible-toggle .mw-collapsible-toggle-indicator img{
height: 20px !important; 
width: 20px !important;
}

/* Collapse indicator image should rotate when toggled*/
#collapse-pre-one:not(.mw-collapsed) .mw-collapsible-toggle .mw-collapsible-toggle-indicator img{
 /* Safari */
 -webkit-transform: rotate(90deg);

 /* Firefox */
 -moz-transform: rotate(90deg);

 /* IE */
 -ms-transform: rotate(90deg);

 /* Opera */
 -o-transform: rotate(90deg);

 /* Internet Explorer */
 filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=1);
}