提升用户体验：实现实时网页加载进度指示条

 #loader_container     {   
    text-align:center;   
    position:absolute;   
    top:40%;   
    width:100%;   
    left:     0;   
    }   
    
    #loader     {   
    font-family:Tahoma,     Helvetica,     sans;   
    font-size:11.5px;   
    color:#000000;   
    background-color:#FFFFFF;   
    padding:10px 0 16px 0;   
    margin:0     auto;     
    display:block;   
    width:130px;   
    border:1px solid #5a667b;   
    text-align:left;     
    z-index:2;   
    }   
    #loader_bg     {background-color:#e4e7eb;   
    position:relative;   
    top:8px;   
    left:8px;   
    height:7px;   
    width:113px;   
    font-size:1px}   
    #progress     {   
    height:5px;