以下内容为转载（对于css码可以自己写当然也可以去网上搜现成的）：
更换背景教学：https://jingyan.baidu.com/album/fc07f9897c730412ffe519c0.html
此背景的css码：（博客皮肤选择darkgreentrip即可）
#home {margin: 0 auto;width: 80%;/*原始65*/min-width: 980px;/*页面顶部的宽度*/background-color: rgba(245, 245, 245, 0.7);padding: 30px;margin-top: 50px;margin-bottom: 50px;box-shadow: 0 2px 6px rgba(100, 100, 100, 0.3);}body {background: rgba(12, 100, 129, 1) url('http://images.cnblogs.com/cnblogs_com/Penn000/1013849/o_123.jpg') fixed no-repeat;background-position: 50% 5%; background-size: cover;}#blogTitle {height: 100px; /*高度*/clear: both;background-color: rgba(245, 245, 245, 0);}#blogTitle h1 {font-size: 36px;font-weight: bold;line-height: 1.8em;/*原始 1.6em*/margin-top: 10px;/*原始 15px */color: #548B54;}#blogTitle h2 {font-weight: normal;font-size: 17px;/*原始 16px ；font-size: 1.0rem;*/ line-height: 1.8;color: #111;font-weight: bold;text-align: right;float: right; }#navigator{background-color: rgba(33, 160, 139, 0.9);}#navList a:link, #navList a:visited, #navList a:active{color: #eee;font-size: 18px;font-weight: bold;}.blogStats{color: #eee;}.postTitle {border-left: 8px solid rgba(33, 160, 139, 0.68);margin-left: 10px;margin-bottom: 10px;font-size: 20px;float: right;width: 100%;clear: both;}.postTitle a:link, .postTitle a:visited, .postTitle a:active {color: #21759b;transition: all 0.4s linear 0s;}.postTitle a:hover {margin-left: 30px;color: #0f3647;text-decoration: none;}.postCon {float: right;line-height: 1.5em;width: 100%;clear: both;padding: 10px 0;}.day .postTitle a {padding-left: 10px;}.day {background: rgba(255, 255, 255, 0.5);}/*文章附加信息*/.postDesc { background: url(images/posted_time.png) no-repeat 0 1px;color: #757575;float: left;width: 100%;clear: both;text-align: left; font-family: "微软雅黑" , "宋体" , "黑体" ,Arial;font-size: 13px;padding-right: 20px;/*5px padding-left: 90px;posted 发表时间左边距离*/margin-top: 20px;line-height: 1.8;padding-bottom: 35px;}.newsItem, .catListEssay, .catListLink, .catListNoteBook, .catListTag, .catListPostCategory, .catListPostArchive, .catListImageCategory, .catListArticleArchive, .catListView, .catListFeedback, .mySearch, .catListComment, .catListBlogRank, .catList, .catListArticleCategory ,#blog-calendar{background: rgba(255, 255, 255, 0.5);margin-bottom: 35px;word-wrap: break-word;}.CalTitle{background: rgba(255, 255, 255, 0);}.catListTitle{background-color: rgba(33, 160, 139, 0.9);}#topics{background: rgba(255, 255, 255, 0.5);}.c_ad_block{display: none;}#tbCommentBody{width: 100%;height: 200px;background: rgba(255, 255, 255, 0.5);}#q{background: rgba(255, 255, 255, 0);}.CalNextPrev{background: rgba(255, 255, 255, 0);}.cnblogs_code{background: rgba(255, 255, 255, 0); }.cnblogs_code div{background: rgba(255, 255, 255, 0); }.cnblogs_code_toolbar{background: rgba(255, 255, 255, 0); }.entrylist{background: rgba(255, 255, 255, 0.5); }