Dab Tsi CSS Qhov Kev Xaiv Tsa?

Cov qauv ntawm cov ntawv HTML yog zoo ib yam li ib tsob ntoo tsev neeg. Hauv koj tsev neeg, koj muaj koj niam koj txiv thiab lwm tus neeg uas tuaj ua ntej koj. Cov no yog koj cov ancestors. Cov me nyuam thiab cov neeg uas tuaj tom qab rau ntawm tsob ntoo ntawd yog nej cov xeeb ntxwv. HTML ua haujlwm zoo sib xws. Cov ntsiab lus uas yog sab hauv ntawm lwm cov ntsiab lus yog lawv cov xeeb ntxwv. Piv txwv li, txij li txhua txhua HTML cov ntsiab lus sab hauv tags, lawv yuav yog tus xeeb leej xeeb ntxwv ntawm qhov "lub cev". Txoj kev sib raug zoo no tseem ceeb heev kom nkag siab thaum koj pib ua hauj lwm nrog CSS thiab xav tau lub hauv paus rau cov ntsiab lus rau kev siv qhov muag pom.

CSS cov neeg xaiv

Tus CSS cov xeeb ntxwv xaiv tau siv rau cov ntsiab lus hauv lwm lub hauv paus (los yog ntau tshaj tau teev, ib lub caij uas yog ib tug xeeb ntxwv ntawm lwm lub caij). Piv txwv, daim ntawv teev npe tsis tau muaj ib daim pib nrog cov cim npe los ntawm cov xeeb ntxwv. Cia peb siv cov HTML hauv qab no ua piv txwv:

qhov no yog ib qhov txuas

LI cov cim npe yog cov xeeb leej xeeb ntawm UL. Tus A lossis yog ib tus xeeb ntxwv ntawm ob leeg LI (me nyuam xeeb tus xeeb ntxwv) thiab UL (xeeb ntxwv xeeb ntxwv). Yog hais tias koj xav txog qhov kev siv qhov kev siv ntoo lub tsev, tus

yuav yog leej niam leej txiv, tus
• yuav yog tus me nyuam tus me nyuam, thiab yuav yog tus me nyuam ntawm
• thiab tus xeeb ntxwv ntawm tus
  .

  Yog li cas koj xav tau cov ntsiab lus hauv cov nplooj ntawv web uas siv cov tub ntxhais kawm xaiv? Ua ntej, koj yuav tsum nrhiav cov xeeb ntxwv xaiv los ntawm kev xaiv ob (lossis ntau dua) hom xaiv uas sib cais los ntawm qhov chaw.

  li ib {ntawv-kho kom zoo nkauj: tsis muaj; }

  Hauv qhov ua piv txwv, cov yeeb yam tsuas yog siv rau lub ntsiab lus txuas () uas yog tus xeeb leej xeeb ntxwv ntawm daim ntawv sau npe (

  • ). Tag nrho lwm cov kev sib txuas ntawm cov nplooj ntawv uas tsis yog tus xeeb leej xeeb ntxwv ntawm ib daim ntawv teev khoom yuav tsis tau txais qhov style no.

    Ib qho tseem ceeb uas yuav tsum nco ntsoov yog tias nws tsis muaj pes tsawg tus cim npe ntawm cov cim npe uas koj siv tau rau hauv koj tus xeeb ntxwv selector. Yog tias ob lub ntsiab lus nyob hauv txhua qhov chaw hauv thawj lub caij nws yuav raug xaiv los ua tus xeeb ntxwv.

    Yog tias koj xav xaiv tag nrho anchors uas tau nqis los ntawm ul ntsiab, koj yuav sau:

    ul ib {ntawv-kho kom zoo nkauj: tsis muaj; }

    Tam sim no, cov yeeb yaj kiab no yuav siv rau txhua qhov txuas uas yog tus xeeb ntxwv ntawm daim ntawv teev khoom. Koj tuaj yeem sau qhov selector no

    ul li ib {ntawv-kho kom zoo nkauj: tsis muaj; }

    Qhov no nws yog ib qho xeeb ntxwv uas siv ntau tshaj ob hom selectors. Hauv qhov no, qhov no yuav siv rau cov kev sib txuas hauv sab nraud ntawm daim ntawv teev npe-yam khoom thiab sab hauv ntawm daim ntawv teev npe uas tsis tau teev npe.

    Siv cov hoob xaiv thiab cov ID Xaiv

    Cov xaiv hais tias koj nyob nraum nqis los ntawm tsis tas yuav tsum yog hom xeeb leej xeeb ntxwv. Piv txwv, xav txog tej yam koj tau muaj ntawm thaj chaw ntawm qhov chaw (xws li kev faib tawm) nrog tus cim ID ntawm "billboard". Koj tuaj yeem teem tau tus xeeb ntxwv selector tawm ntawm tus ID:

    #billboard ul {keeb kwm xim: #ccc; }

    Qhov no yuav ua rau daim ntawv teev npe uas tsis tau teev npe uas yog tus xeeb ntxwv ntawm lub caij nrog tus ID "billboard". Koj tuaj yeem ua tib yam rau cov nqi hauv chav kawm.

    div.billboard ul {background-xim: #ccc; }

    Qhov no pom tau hais tias qhov kev faib khoom muaj nqi ntawm "billboard". CSS saum toj no yuav ua kom tus

    element hauv txhua pawg uas muaj qhov kev ntaus nqi no.

    Koj tuaj yeem tau txais hnyav-tes thiab qhia nrog cov xeeb ntxwv xaiv. Piv txwv, yog tias koj siv Dreamweaver los sau koj cov HTML code , muaj qhov chaw thaum koj ntxiv CSS cov cai tshiab uas yuav pib tsim lub selector raws li qhov kev tso kawm ntawm koj tus cursor ntawm nplooj ntawv ntawd. Dab tsi Dreamweaver nyob rau hauv no tus qauv yog tsim ib qho kev hais lus wildly thiab cov xeeb ntxwv ntev selector. Ntawd qhov tseem ceeb tsis tsim nyog rau koj qhov CSS los ua haujlwm. Qhov koj xav ua yog nrhiav tau qhov sib txawv ntawm tus xeeb ntxwv selector uas muaj qhov tshwj xeeb txaus kom koj tuaj yeem siv cov ntsiab lus uas koj xav tau (tsis muaj styling ones koj tsis xav) tsis muaj CSS cov cai uas muaj cov xaiv uas muaj ntau tshaj loj.