.sidebar{
height:680px;
width:250px;
float:right;
text-align:left;
font-size:17px;
font-weight:700;
border:2px solid white;
margin:15px; 
border-radius:4px;
background:#999999;
background:rgba(0,0,0,.3);
}
.sidebar img {
width:100%;padding:10px;
}
.sidebar ul{
margin-right:15px;
}
.sidebar ul li{
text-align:left;
margin-top:15px;

}

@media (max-width:655px){
.sidebar{
height:680px;
width:250px;
float:none;
text-align:left;
font-size:17px;
font-weight:700;
border:2px solid white;
margin-left:auto;
margin-right:auto;
border-radius:4px;
background:#999999;
background:rgba(0,0,0,.3);
}
}