style.css

main{margin-top:5px}.row a{display:block;margin:5px 48px;height:100px;border-radius:10px;background-color:#808080;color:#fff;text-align:center;line-height:100px;vertical-align:middle;text-decoration:none;font-family:"微软雅黑";font-size:18px;-webkit-transition:background 1s,color 1s;-moz-transition:background 1s,color 1s;-ms-transition:background 1s,color 1s;-o-transition:background 1s,color 1s;transition:background 1s,color 1s}.row a:hover{background-color:#fff;color:#000;border:2px solid #000}.jumbotron{background-image:url("sw-2.jpg");width:1140px;height:300px;margin:51px auto 0 auto;padding:0}.smoke{position:absolute;width:1140px;height:300px;left:50%;margin-left:-570px;padding:0;opacity:.6;background-image:url("smoke.png")}.my-position{position:absolute;z-index:99;margin:51px 200px;vertical-align:middle}.dropdown-toggle{display:inline}.dropdown-inverse{background-color:#222;color:#9d9d9d}.dropdown-inverse li a{color:#9d9d9d}