header{
        width: 980px;
        height: 220px;
        background:      #0a92e0;
        margin: 10px auto;
        border: 20px dashed #7e81a3;
        background-clip: border-box;
    
       }
       nav h2{
        width: 150px;
        background-color: #ff3da8;
        padding:12px 48px ;
        border-radius: 70px;
        
    }
    nav.tomcang h2{
        color: rgb(20, 220, 110);
        margin-top: 30px;
        text-decoration: none;
    }
nav.tomcang a{
    text-decoration: none;
    color: #45dd66;
}


 body.anh{
     background-image: url(http://2.bp.blogspot.com/-MobBV7yKrJY/UgR8c_h1sAI/AAAAAAAACmk/x211qftvLRs/s1600/anh-dep-ve-bien-3.jpg);
 }
 
 body{
    -webkit-touch-callout: none;
          -webkit-user-select: none;
          -moz-user-select: none;
          -ms-user-select: none;
          -o-user-select: none;
           user-select: none;
}