%content {
     font-size: 32px;
     text-align: center;
     margin: 0 5px;
 }
.bin {
    @extend %content;
    min-height: 150px;
    min-width: 150px;
    float: left;
    border: 1px solid red;
    padding: 20px;
}
.item {
    @extend %content;
    min-height: 150px;
    min-width: 150px;
    background: blue;
    float: right;
    transition: all 0.2s ease;
}
.drag {
    opacity: 0.5;
}
.over {
    background: red;
}