.hoge:nth-child(2) {
background-color: #ddd;
}
.hoge:first-child {
background-color: #ddd;
}
.hoge:last-child {
background-color: #ddd;
}
偶数
.child:nth-child(even) {
background-color: #ddd;
}
奇数
.child:nth-child(odd) {
background-color: #ddd;
}