この効果は、純粋なcssを使用して実現できます。
HTML
<li class="menu-item menu-item-type-post_type menu-item-object-page menu-item-58" id="menu-item-58">
<a href="http://ranchocordovaeventscenter.com/?page_id=57">Building Facts</a>
<div>
<div class="wrap-behind"></div>
</div>
</li>
CSS
#extra-navbar .menu-item {
margin-bottom: 0.9rem;
margin-left: 20px;
}
.wrap-behind {
background: none repeat scroll 0 0 #F9B233;
border-left: 13px solid transparent;
border-right: 1px solid #053053;
border-top: 10px solid #053053;
float: left;
height: 0;
width: 0;
}
#extra-navbar ul li {
background-attachment: scroll;
background-color: #104571;
background-position: left bottom;
background-repeat: no-repeat;
color: #FFFFFF;
overflow: visible;
}