@media screen and (max-width: 640px)  {
    #left{display:none}
    #right{width:100%;}
    #right section{width:calc(100% - 3em)}
    
}
@media screen and (min-width: 640px)  {
    #left{display:flex}
    #right{width:calc(100% - 204px - 5em);}
    #right section{width:calc(50% - 3em);height: calc(50% - 3em)}
}
@media screen and (min-width: 990px) {
    
}
@media screen and (min-width:1200px) {
    
}
main{    
    font-size:16px;   
}
.box{    
    border-radius: 0.5em;
    background-color: white;
    border:1px solid #2085d5;
}
main #left{
    width:calc(202px + 3.5em);
    flex-direction: column;
    padding:0;
    margin:0;

}
main #left #book{
    width: calc(200px + 2em);
    height:calc(278px + 2em);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;    
    margin:1em 0.5em 0.5em 1em;
}
main #left img{
    width:200px;
    height:278px;
    border-radius: 0.5em;
}
main #left #menu{
    width:calc(100% - 3.5em);
    display:flex;
    flex:1;      
    margin: 0.5em 0.5em 1em 1em;
    padding:1em;
}
main #left #menu ul{
    margin:0;
    padding:0;
    width:100%;
    height:100%;
    display:flex;
    flex-direction:column;
}
main #left #menu ul li{
    list-style-type:none;
    padding:0.5em 1em;
    margin:0.5em;
    border-radius:1em;
    background-color: #809fe3;
    text-shadow:0.05em 0.05em 0.05em rgba(0,0,0,1);
}
main #left #menu ul li a{
    font-size:16px;
    display:block;
    width:100%;
    color:#FFF;
    text-align:center;
    text-shadow:0.05em 0.05em 0.05em rgba(0,0,0,1);

}
main #right{
    margin:1em 1em 1em 0.5em;
    padding:0.5em 0 0 0;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
}
main #right section{
    margin:0.5em;
    padding:1em;
}
main #right section h4{
    background-color:#809fe3;
    color:#FFF;    
    text-shadow:0.05em 0.05em 0.05em rgba(0, 0, 0, 1);
    margin:0;
    border-radius:1em;
    padding:0.5em;
    text-align: center;

}
main #right #introduction{
    
}
main #right #team{

}

main #right #content{

}
main #right #video{

}