Add margin-top and change values according to your will.
@media (min-width: 640px) {
#watson-float {
margin-top: 100px;
top: 0;
right: 0 !important;
}
#watson-box {
width: -900% !important;
height:100% !important;
}
#message-container {
height: calc(100% – 2.75em) !important;
}
}