canvas#myCanvas{
    float:left;
    outline:1px solid black;
}
.unselectable {
    -webkit-user-select: none; /* Safari */        
    -moz-user-select: none; /* Firefox */
    -ms-user-select: none; /* IE10+/Edge */
    user-select: none; /* Standard */
}   
*{
    background-color: #f7ffff;;
}
#GoBack{
    /*make it fixed on a position*/
    position: fixed;
    margin-top: 30px;
    right: 0;
    top: 0;
    display: flex;
    flex-direction: column-reverse;
    align-items: center;
    /*make border*/
    border-left: 1px solid black;
    border-radius: 20px 0 0 20px;
    border-top: 1px solid black;
    border-bottom: 1px solid black;
	background-color: #e3f1ff;
	margin-left: 15px;
}
#GoBack img{
    margin: 10px;
    background-color: transparent;
}
body{
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 0;
}
canvas{
    width: 1000px;
}
h2{
    margin-top: 20px;
    margin-bottom: 0;
}
h3{
    margin-top: 0;
}