CSS背景图拉伸不变形在线效果体验：http://hovertree.com/texiao/mobile/3.htm
请使用手机浏览器查看。
css代码：
.bg{ background:url(http://hovertree.com/texiao/mobile/3/hovertree01.jpg); filter:"PRogid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='scale')"; -moz-background-size:100% 100%; background-size:100% 100%; }
HTML文件代码：
<!DOCTYPE html><html><head><meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" /><title>DIV缩放背景自适应(不变形)jQuery-HoverTree</title><style type="text/css">a {color: white;}body {font-family: 幼圆,宋体,'Times New Roman', Times, serif;color:white;}.picwidth {width: 100%;text-align: left;filter: "progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='scale')";-moz-background-size: 100% 100%;background-size: 100% 100%;}body {margin: 0px;background-color: #120c0c;}.content {width: 206px;margin: 0px auto;padding-top: 10px;line-height: 16px;}.frame {width: 256px;margin: 0px auto;}</style><script src="http://hovertree.com/ziyuan/jquery/jquery-2.1.4.min.js"></script></head><body><div class="frame"><div id="contentHead" style="height:231px;background-image:url(http://hovertree.com/texiao/mobile/3/hovertree01.jpg)" class="picwidth"><input type="button" value="放大" id="keleyibig" /><input type="button" value="缩小" id="keleyismall" /><a href="http://hovertree.com/hvtart/bjae/f43r3qry.htm">原文</a></div><div id="contentBody" style="background-image:url(http://hovertree.com/texiao/mobile/3/hovertree02.jpg);height:99px;color:White;" class="picwidth"><div class="content">今日人物：<div style="text-align:center">谢霆锋</div><br />请点击放大,缩小按钮。</div></div><div id="contentBottom" style="background-image:url(http://hovertree.com/texiao/mobile/3/hovertree03.jpg);height:124px" class="picwidth">DIV缩放背景自适应(不变形)<br />请使用支持HTML5的浏览器查看本页<br /><a href="http://hovertree.com/texiao/">特效库</a> <a href="http://hovertree.com">首页</a> <a href="http://keleyi.com">柯乐义</a> <a href="http://hovertree.com/hvtart/bjae/f43r3qry.htm">原文</a></div></div><script>$(function () {$(".frame").width(300);var documentWidth = $(document.body).width();if (documentWidth < 600)$(".frame").width(documentWidth);var cHead = $("#contentHead"); var cBody = $("#contentBody"); var cBottom = $("#contentBottom");function setHeight() {cHead.height(((cHead.width() / 320) * 289));cBody.height(((cBody.width() / 80) * 31));cBottom.height(((cBottom.width() / 64) * 31));}setHeight();$("#keleyibig").on("click", function (){$(".frame").width($(".frame").width() + 50)setHeight();})$("#keleyismall").on("click", function () {$(".frame").width($(".frame").width() - 50)setHeight();})})</script> </body></html>
Web前端资源：http://www.cnblogs.com/jihua/p/webfront.html
这张图可作为手机屏幕背景