:first-child

一番最初のヤツに

• 1
• 2
• 3
• 4

li:first-child{background:#e1f5a9;;}

:last-child

一番最後のヤツに

• 1
• 2
• 3
• 4

li:last-child{background:#e1f5a9;;}

:nth-child(n)

n番目のヤツに

• 1
• 2
• 3
• 4

li:nth-child(2){background:#e1f5a9;}

:nth-child(odd)

奇数番目のヤツに

• 1
• 2
• 3
• 4

li:nth-child(odd){background:#e1f5a9;}

:nth-child(even)

偶数番目のヤツに

• 1
• 2
• 3
• 4

li:nth-child(even){background:#e1f5a9;}