.panel{display:block;width:100%}div.panel{background-color:#fff;border:1px solid #bbb}.panel .panel-header{display:block;cursor:pointer}div.panel .panel-header{background-color:#eee;padding:10px}div.panel .panel-header::before{content:"▶";color:#555}.panel .panel-content{display:none;padding:10px}.panel.panel-active>.panel-content{display:block}.panel.panel-active>div.panel-header{background-color:#ddd;box-shadow:inset 0px 0px 3px 1px #ccc;font-weight:bold}.panel.panel-active>div.panel-header::before{content:"▼"}.panel-group .panel:not(:last-child){border-bottom:0px}