Dab tsi "Cascade" txhais tau tias nyob rau hauv Cascading Style Sheets?

Cascading Style Sheets los yog CSS raug teeb tsa kom koj muaj peev xwm muaj ntau yam khoom uas cuam tshuam rau tib lub caij. Qee yam ntawm cov khoom yuav sib ceg nrog ib leeg. Piv txwv, koj tuaj yeem teev cov xim liab ntawm cov pawg lus thiab tom qab ntawd, tom qab ntawm, muab cov xim xim xiav. Tus browser paub qhov xim twg los ua cov pawg lus li cas? Qhov no yog txiav txim siab los ntawm cascade.

Hom Phaub Vias

Nws muaj peb hom ntawm cov ntawv sau style:

1. Sau Cov Ntawv Xeem Ntawv
   1. Cov no yog cov ntawv txheeb uas tsim los ntawm tus kws sau ntawv ntawm nplooj ntawv Web. Lawv yog cov neeg xav li cas thaum lawv xav txog CSS cov ntawv txheeb.
2. Tus Neeg Siv Ntawv Cov Ntawv Xaiv
   1. Tus neeg siv cov ntawv twv raug tsim los ntawm tus neeg siv ntawm qhov Web page. Cov no pub rau tus neeg siv kom muaj kev tswj ntau dua li cov nplooj ntawv pom.
3. Tus Neeg Siv Cov Ntawv Xam Xaj Tswv
   1. Cov qauv no yog qhov Web browser siv rau nplooj ntawv los pab saib cov nplooj ntawv. Piv txwv, nyob rau hauv XHTML, feem ntau pom cov neeg siv khoom pom cov lossis lossis cov ntawv nyeem. Qhov no txhais nyob rau hauv tus neeg siv khoom daim ntawv qhia cov ntawv.

Cov khoom uas tau hais tseg rau hauv txhua daim ntawv sau saum toj no yog muab qhov nyhav. Los ntawm lub neej ntawd, tus sau daim ntawv muaj qhov hnyav tshaj plaws, ua raws li tus neeg siv cov ntawv style, thiab thaum kawg los ntawm tus neeg siv khoom daim ntawv qhia daim ntawv. Qhov tsuas yog kos rau qhov no yog nrog txoj cai ! Tseem ceeb hauv cov neeg siv style ntawv. Qhov no muaj hnyav dua li tus sau phau ntawv style.

Cascading Order

Txhawm rau daws cov teeb meem, Web browsers siv qhov kev txiav txim nram qab no los txiav txim xyuas seb qhov twg muaj qhov zoo tshaj plaws thiab yuav siv:

1. Ua ntej, saib tag nrho cov lus tshaj tawm uas siv rau lub ntsiab lus nug, thiab rau hom ntawv xov xwm.
2. Ces saib dab tsi style ntawv nws tuaj ntawm. Raws li saum toj no, cov ntawv sau style tuaj thawj, ces tus neeg siv, ces tus neeg siv khoom siv. Nrog! Tseem ceeb tus neeg siv yeej muaj ntau dua nqis tshaj tus sau! Tseem ceeb heev.
3. Qhov tshwj xeeb tshaj plaws ntawm tus selector yog, qhov ntau nqis nws yuav tau txais. Piv txwv, ib style ntawm "div.co p" yuav muaj ib qho siab dua qhov ntawm ib qho ntawm "p" lossis.
4. Thaum kawg, xaiv cov cai los ntawm qhov kev txiav txim lawv tau txhais. Cov kev cai uas tau hais tseg tom qab hauv daim ntawv ntoo muaj ntau dua qhov uas tau hais tseg ua ntej. Thiab cov cai ntawm ib daim ntawv qhia tawm txawv teb chaws raug suav ua ntej ua cov cai ncaj nraim rau hauv daim ntawv sau style.