/* first-child */
.list li:first-child {
color: red;
}
/* last-child */
.list li:last-child {
color: red;
}
/* nth-child() */
/* odd even 2n */
.list li:nth-child(4) {
color: red;
}
.content p:nth-child(2n+1) {
color: red;
}
/* :nth-of-type() */
.content p:nth-of-type(2n) {
color: red;
}