#a > a,
#a-a > a,
#a-aa-aa > a {
    color: #f00;
    padding: 20px 15px 20px 65px;
    background-repeat: no-repeat;
    background-position: 10px center;
    background-image: url('../images/x.png')
}
* {
    margin: 0;
    padding: 0
}
.tree ul {
    padding-top: 20px;
    position: relative
}
.tree li {
    float: left;
    text-align: center;
    list-style-type: none;
    position: relative;
    padding: 20px 5px 0 5px
}
.tree li::before,.tree li::after {
    top: 0;
    width: 50%;
    right: 50%;
    content: '';
    height: 20px;
    position: absolute;
    border-top: 1px solid #ccc
}
.tree li::after {
    left: 50%;
    right: auto;
    border-left: 1px solid #ccc
}
.tree li:only-child::after,.tree li:only-child::before {
    display: none
}
.tree li:only-child {
    padding-top: 0
}
.tree li:first-child::before,.tree li:last-child::after {
    border: 0 none
}
.tree li:last-child::before {
    border-right: 1px solid #ccc;
    border-radius: 0 5px 0 0
}
.tree li:first-child::after {
    border-radius: 5px 0 0 0
}
.tree ul ul::before {
    top: 0;
    width: 0;
    left: 50%;
    content: '';
    height: 20px;
    position: absolute;
    border-left: 1px solid #ccc
}
.tree li a {
    color: #666;
    font-size: 24px;
    padding: 5px 10px;
    border-radius: 5px;
    text-decoration: none;
    display: inline-block;
    border: 1px solid #ccc;
    font-family: arial,verdana,tahoma
}
.tree li a:hover,.tree li a:hover+ul li a {
    border: 1px solid #94a0b4
}
.tree li a:hover+ul li::after,.tree li a:hover+ul li::before,.tree li a:hover+ul::before,.tree li a:hover+ul ul::before {
    border-color: #94a0b4
}