/* ------------ ่ฆชๅญ้ไฟ ------------ */
/* ไธไธๅฎๆฏ็ดๆฅ็่ฆชๅญ้ไฟ */
ancestor descendant /* op: space */
/* ็ดๆฅๅญๅ
็ด */
parent > direct-child
/* ็ดๆฅๅญๅ
็ด ๏ผไฝไธๆฏ็ฌฌไธๅ(ไปฅไธๅฏซๆณๆๆ้ฝไธๆจฃ) */
parent > direct-child + next-siblling /* immediate sibling */
parent > :not(:first-child)
parent > :nth-child(n+2) /* n = 0, 1, 2 ... */
/* ๆฒๆๅญๅ
็ด ็ๅ
็ด (ๆๅบๅฑค) */
:not(:has(*)) /* :has() ็บ CSS4 ๅ่ฝ */
/* ------------ ๅ
ๅผ้ไฟ ------------ */
/* (็ท้ฐ่็)ไธไธๅๅ
ๅผ(next sibling) */
brother + next-younger-brother
/* ๅพ้ข็ๅ
ๅผ(following sibling) */
older ~ younger /* ไธๅฟ
ไธๅฎ่ฆ็ทๆฅ่็ */