前面一个CSS教程介绍了在网页中利用CSS建立立体表格效果，今天给大家来一篇很不错的鼠标悬停效果，也是用CSS实现的。

这是一个很棒的鼠标悬停（hover）效果。从国外的网站上看到了，转载过来。没有作任何翻译与编辑，大家可以偿试阅读英文教程，加油！

注意：此悬停效果在IE6中无效

实例预览地址：http://www.prukc.com/

IwouldliketosharesomeinsightonapieceofCSSI’veusedforthehomepageforawebsiteawhileagothatI’vebuilttogetherwithRogerJohansson.

TheHTMLmarkup

Let’stakealookfirstattheHTMLmarkupforthis.Firstweneedtothinkaboutthestructureofthispieceofcontent.HowshoulditbestructuredwithCSSdisabledandstillmakesensefortheuser.Ithinkabulletlistmakessense.Wesumupthe4differentwaystofindyourKansasCityHomesforSale.Thisisthe(X)HTMLmarkup:

HTML： <h2>4differentwaystofindyourKansasCityHomesforSale</h2>

<ulid="differences">

<liid="diff-1"><h3><em>1</em><ahref="benefits.html">SeeallMLShomeslikeaninsider—joinus</a></h3><div><p><ahref="benefits.html">Joinus</a>andsee<strong>2,207</strong>additionalhomes,e-mailupdates,andfreecustomwebsite.</p></div></li>

<liid="diff-2"><h3><em>2</em>Whatismyhouseworth?</h3><div><p>Findthe<ahref="/"title="empty">valueofyourhome</a>fromanyofouragentswithourcompetitivemarketanalysis.</p></div></li>

<liid="diff-3"><h3><em>3</em>Google™searchKansasCityareahomesinMLS</h3><div><p><ahref="/"title="empty">SearchvirtuallyallMLShomes</a>inthegreaterKansasCityareabyusingGoogle™.</p></div></li>

<liid="diff-4"><h3><em>4</em>MapKansasCityrealestateinGoogle™maps</h3><div><p><ahref="cma.html"title="empty">Seethelocation</a>ofallKansasCityrealestatewithGoogle™maps—maporsatelliteviews.</p></div></li>

</ul>

IfyoulookatethepagewithCSSdisabled,Ithinkthismarkupiswellstructuredandit’sperfecttobuildthenecessaryCSStoachievethestyleIhaveinmind.

Thebackgroundimages

IfyoulookatthefinalpageandtheeffectIwanttoachievewiththetabs,youknowthatIneedtocreatebackgroundimagesforthisthatareabletogrowiftheuserenlargesthetext.Hereishowtheylook:

diff-tabs-top-wide.gif

diff-tabs-bottom-wide.gif

You'llnoticethatboththehoverbackgroundandthedefaultbackgroundaresavedas1giffile.Thiswaythehovereffectwillgosmoothwithoutinteruption.Theentireimageisloadedandthebrowserdoesn’thavetoloadthehoverimagesonthemomenttheuserhoversthebox.Tobesuretheboxcangrowwesavethebottompartoftheboxandthetoppartofthebox,makingitlongenoughtobesuretherewillbenogaps(tillacertainenlargement).

TheCSSstyles

Theunorderedlist“differences”

ThisistheCSSfortheliststartingwiththeunorderedlistofthe4boxes.TopreventthemarginstocollapseI’veaddedfloat:left. #differences{

margin:0.5em01.5em0;

padding:0;

list-style:none;

width:100%;

float:left;

}

Thelielementstyleslooklikethis:

#differencesli{

margin:018px00;

padding:0;

float:left;

background:url(../images/diff-tabs-top-wide.gif)no-repeat00;

}

Iaddaright-marginof18pxtocreateagutterbetweeneachbox.Thelastboxintherowdoesn’tneedthismargin.Eachlielementhasanid.Theidforthelastoneis#diff-4.SoIaddthisCSSstyle:

#differencesli#diff-4{

margin-right:0;

}

Makingsurethetabbedboxescangrow

Asyou’venoticed,we’velinkedthetoppartofthebackgroundimage(thetabshape)tothelielementviaCSS.Tomakesurethetabbedboxescangrowiftheuserenlargeshistext,weneedtoaddanextradivineachlielement.ThiswaywecanlinkthebottompartoftheimagetothisdivviaCSS:

#differencesdiv{

font-size:0.94em;

padding:6px;

background:url(../images/diff-tabs-bottom-wide.gif)no-repeat0100%;

}

WithCSS3wedon’thavetogothroughthishassleofaddingextradivs,becauseCSS3allowsformultiplebackgroundimagesononeelement.ThisismytopfavoriteCSS3feature:)

Creatingthehovereffect

I’veusedbackgroundpositioningtocreatethehovereffectonthelielementusingthe:hoverpseudo-class.TheCSSlookslikethis:

#differencesli:hover{

background-position:-156px0;

}

#differencesli:hoverdiv{

background-position:-156px100%;

}

Thexcoordinateissetto-156px.Thiswaythepinkorangepartofthebackgroundimagewillbeshown.Thefirststylerepresentsthetoppartofthetabbedboxandthe2ndonethebottompart.RememberIhadtoaddanextradivtomakesuretheboxcangrow(tillacertainenlargement).

Thepageusesadynamicresolutiondependentlayout

Notsureifyou’venoticedornot,butifyouresizeyourbrowserwindowtolessthen750pixelswide,thepagewilladjustitslayout.ThisisdoneusingajavascriptcreatedbyKevinHaleofParticleTreeincombinationwithCSS.I’musinganextraCSSstylesheetthatisappliedifthebrowserwindowisresizedtolessthen750pixels.Bydefaultthepage/siteusesthewiderversion,whichisaimedtoascreenresolutionof1024x768.About90%ofthevisitorsofthePrudentialKansasCityvisitorsareusingascreenresolutionofatleast1024x768pixels.

HopefullysomeofyouhavelearnedfromthisarticleandareinspiredtouseCSSinacreativewaywithoutoverlookingtheaccessibilitypartofitandkeepingtherightstructureinmindforthe(X)HTML.I’mstillcreatingnewtemplatesforthiswebsiteonanoccasionalbasis.Thiswebsiteisratherbigandnewfeaturesareconstantlyaddedbytheclientandthedeveloper.

Ohandlet’snotforgettomentionthatitisalwaysgreattoworktogetherwithRoger.He’spickyinwhathedoes,butthat’swhatIloveaboutworkingwithhim,andofcourseIalwayschallengehimwithmydesigns:)

Previewurl:http://www.prukc.com/