body{
 padding: 0px;
 margin: 0px;
}

.mainDiv{
 display: flex;
 width: 100%;
}
.leftNav{
 width: 16%;
 background-color: #c0c0c0;
 color:#333;
 font-size:24px;
 height: 1000px;
 padding: 20px;
}
.rightMain{
 width: 84%;
 height:1000px;
 background-color: #fff;
 font-size:20px;

}
.topNav{
 height:50px ;
 background-color: #cfdefd;
}
.topNav ul{
 display: flex; 
 margin: 0px;
 padding: 0px;
}
.topNav li{
 padding: 10px;
 text-align: center;
 list-style: none;
}
.videoContent{
 padding:20px;
}