.column {
min-width: 100px;
float: left;
padding-bottom: 100px;
}
.portlet {
margin: 0 1em 1em 0;
}
.ui-sortable-placeholder {
border: 1px dotted black;
visibility: visible !important;
height: 50px !important;
}
.ui-sortable-placeholder * {
visibility: hidden;
}