.b {
        background-position: left top;
        width: 25px;
        height: 160px;
        display: inline-block;
        background-repeat: no-repeat;
        margin-left: -4px;
    }
    
    .b1 {
        background-image: url('../img/b1.png');
    }
    
    .b2 {
        background-image: url('../img/b2.png');
    }
    
    .b3 {
        background-image: url('../img/b3.png');
    }
    
    .n {
        background-position: left top;
        width: 16px;
        height: 104px;
        display: inline-block;
        background-repeat: no-repeat;
        position: absolute;
        z-index: 5;
    }
    
    .n1 {
        margin-left: -13px;
        background-image: url('../img/n1.png');
    }
    
    .n2 {
        margin-left: -12px;
        background-image: url('../img/n1.png');
    }
    
    .part1 {
        "width:2500px; display:inline-block; 

    }
    
    .part2 {
        width: 2500px;
        background-color: #000000;
        margin-top: -1px;
        height: 160px;
        display: block;
    }
    #piano_container {
        
        white-space: nowrap;
        left: 50%;
        margin-left: -764px;
        top: 50%;
        margin-top: -476px;
        height: 100%;
        user-select: none;
        -moz-user-select: none;
        -khtml-user-select: none;
        -webkit-user-select: none;
        -o-user-select: none;
    }
    
    .column {
        height: 100%;
        float: left;
        width: 50%;
        border-bottom-style: solid;
        border-bottom-color: black;
        
     -webkit-box-shadow: -3px 0px 0px 0px rgba(0,0,0,0.75);
-moz-box-shadow: -3px 0px 0px 0px rgba(0,0,0,0.75);
box-shadow: -3px 0px 0px 0px rgba(0,0,0,0.75);   
        
        
    }
    
    .row:after {
        display: table;
        clear: both;
    }