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IthoughtI'dsharesomeofmyhabitswhenitcomestodoingCSSworkandletmewarnyou,someofwhatIhavetosayisprobablyalittlecontroversial.Butwhat'slifewithoutlivingitontheedge.(Yeah,IliveanexcitinglifewhenCSSisconsidered'theedge'.)

pxforfontsizes-用px作为字体大小的单位

Sacrilege,Iknow.ThereareperfectlygoodwaystogetconsistentfontsizingandIreallyshouldusethembutInternetExploreristheonlybrowserthatIcanthinkofthatdoesn'tresizetext.IfthemajorityofyouraudienceusesIE,thenbenicetothemanddon'tusepixels.Otherwise,IfigurewithIE7supportingit,pixelsarethenewems.

Whenusingpixelsizes,Ialsogettobesparinginmyusage.Ispecifyitonthebodyandanyheadersthatneedit.Inheritanceislessofanissue(howmanysiteshaveyouseenlistitemsinexplicablysmallerthantherestofthecontentlikeitwaslessimportant).

CSSdeclarationsononeline-CSS声明写在一行

I'vealwaysputmyentiredeclarationononeline.Here'sanexampletoexplainwhatImean:

h2{font-size:18px;border:1pxsolidblue;color:#000;background-color:#FFF;}

h2{

font-size:18px;

border:1pxsolidblue;

color:#000;

background-color:#FFF;/*www.jb51.net*/

}

Thesecondonemaylookprettierbutitsuredoesn'thelpmefindanything.Whenlookingforsomethinginastylesheet,themostimportantthingistheruleset(that'sthepartbeforethe{and}).I'mlookingforanelement,anidoraclass.Havingeverythingononelinemakesscanningthedocumentmuchquickerasyousimplyseemoreonapage.OnceI'vefoundtherulesetIwaslookingfor,findthepropertyIwantisusuallystraightforwardenoughastherearerarelythatmany.

BlockingtheStyles-代码分块

Ibreakdownmystylesheetintothreeseparateblocks.Thefirstisstraightelementdeclarations.Changethebody,somelinksstyles,someheaderstyles,resetmarginsandpaddingonforms,andsoon.ThisisusuallyasmallblockasIonlyliketoredefinewhatIneedto.Noglobalmarginandpaddingresetforme.Iclearthebodyandformandmaybeadjustparagraphifthedesignreallyneedsit.Otherwise,letthebrowserhandleit.Ifindthemoreyoutrytooverridewhatthebrowserdoes,themorestylesyouhavetoputin,whichsimplyaddstothetimetotrackdownbugsandmaintainthecode.

Afterelementdeclarations,Ihavemyclassdeclarations;thingslikeclassesforanerrormessageoracalloutwouldgohear.Iusuallyonlyhaveacoupleofthese.

Finally,themeat.Istartbydeclaringmymaincontainersandthenanystylesforelementswithinthosecontainersareindented.Ataquickglance,Icanseehowmypageisbrokendownandmakesiteasiertoknowwheretolookforthings.I'llalsodeclarecontainerseveniftheydon'thaveanyrules.

#content{float:left;}

#contentp{...}

#sidebar{float:left;}

#sidebarp{...}

#footer{clear:both;}

#sidebarp{...}/*www.jb51.net*/

BrowserSupport-浏览器兼容

Supportonlythelatestbrowsers.ThatmeansdroppingsupportforIE5andIE5.5.Lotsoftimeandefforttobesavedhere.NoboxmodelhacksneededforIE6.Infact,insupportingjustthemostrecentversionsofbrowsers,Iendupusingveryfewhacks.AlongwithusingveryfewhacksmeansIcanavoidshovellingdifferentstylesheetstoseparatebrowsers.Ihaveonesheet,andthat'sit.AnyhacksIdousearenormallycommentedassuch.Similartotheuseofpixelmeasurements,youhavetoconsideryouraudiencebeforedroppingbrowsersupport.

ThebiggestthingformeisstilltriggeringhasLayoutinIEtodofloatcontainmentandI'vebeenusingzoom:1forthat.Ilikeitbecauseit'sinnocuousandshouldn'tmesswithanythingelse.

ContainingFloats-“包含”式浮动

Ijusttouchedonfloatcontainmentsolet'sexpandonthat.Mycurrentapproachtocontainingfloatsisusingoverflow:hidden(withpossiblyzoom:1forInternetExplorer).Noclearingdivoruseof:after.Onlyworryaboutcontainingyourfloatsifyouhaveabackgroundyouaretryingtosetonyourcontainer.Theoverflowshouldbesetonthecontainer.

Keepinmindthatthecontentwithinthecontainershouldbedesignedtostaywithinthecontainer.Anythingtoobigandit'llgetclipped.Shiftingthingsusingnegativemarginsoutsidethecontainerwillalsogetclipped.

UnderstandOverflow-理解与使用溢出

OverflowisusuallywherepeoplegetbitbyIE.Ifyou'vegottwofloatedelementsandthecontentfromtheleftcontaineroverflowsthen,inIE,thecontainergrowsandinevitablypushestherightcontainerbelowit.Thisisusuallyasignthatyou'vemessedupyourmargins,widths,orpaddingononeofthesecontainersbutFirefox(etal)won'trevealthis.Usingsomethinglikeoverflow:hiddenoroverflow:scrollonacontainercanhelppreventIEfromallowingthecontenttopushthewidthofthecontainerbutyou'rebetterofftryingtofixtheissueinthedesign.

AllowBlockElementstoFillTheirSpaceNaturally-允许块元素的空白

Myruleofthumbis,ifIsetawidth,Idon'tsetmarginorpadding.Likewise,ifI'msettingamarginorpadding,Idon'tsetawidth.Dealingwiththeboxmodelcanbesuchapain,especiallyifyou'redealingwithpercentages.Therefore,Isetthewidthonthecontainersandthensetmarginandpaddingontheelementswithinthem.Everythingusuallyturnsoutswimmingly.

UseCSSShorthand-使用CSS属性缩写

ThismightseemlikebeatingadeadhorsebutIstillseepeopledoingreallyverbosestatementswherethey'resettingmargin-top,margin-right,margin-bottomandmargin-left.Mygeneralruleofthumbis,youcanusethelongformonlyifyou'resettingoneside.Onceyouhavetosetmorethanoneside,it'lltakelessbytestouseshorthand.

Inshorthand,rememberthatthepropertiesstartatthetopandworkclockwise.margin:toprightbottomleft;It'salsohandytoknowtheshorterformsifyouhaveequalvaluesfortopandbottomorleftandright.

margin:5px10px20px;/*topleft/rightbottom_www.jb51.net*/

margin:10px20px;/*top/bottomleft/right*/

margin:0;/*allsides*/

Forborder,ifyouonlyhavetosetmorethanonesidedifferentlythenusetwodeclarations.Thefirsttosetallsides,andthenasecondtochangethevaluesforoneoftheproperties.

/*1pxblueborderontheleftandbottom_www.jb51.net*/

border:1pxsolidblue;border-width:001px1px;

AvoidUnnecessarySelectors-避免多余的选择器

Justspecifytheminimumnumberofselectorsnecessaryforthestyle.Ifyoufindyourselfdoingulli{...}ortabletrtd{...}thenyou'rebeingmoreverbosethanyouneed.LI'swillinevitablybeinUL's(okay,IsupposetheycouldfindthemselvesinOL's,inwhichcase,bemorespecificforthosestyles)andaTDwillinevitablybeinaTRandaTABLE.

OrputtingtheelementnameinfrontofanIDselector(Example:div#navigation).Iusedtodothisbecauseit'dhelpme"remember"whichelementtheIDison.Asitturnsout,Itendtousesimilarclassnamesfromprojecttoprojectandtheyinevitablyappearonthesameelements.Ialsotendtojustdoasearchtofindwheresomethingis.So,thesedays,Ijustleaveitat#navigation.

Usinglessselectorswillmeanlessselectorswillbeneededtooverrideanyparticularstyle—thatmeansit'seasiertotroubleshoot.

KeepitSimple-保持简洁

Ifithasn'tbeenevidentthroughoutthispost,onlyaddwhenyouneedto,andthatincludeshacks.Noneedtogetanymorecomplicatedthanyouneedto.

Now,I'dlovetohearsomeofyourtips.