.canvas-board{
    position: fixed;top:50px;left:0;
}
.canvas-tool{
    position: fixed;height:40px;top:0;left:0;padding-left: 5px;
}
.canvas-tool .canvas-tool-item{
    width:50px;height:50px;padding: 5px;cursor: pointer;box-sizing: border-box;line-height: 50px;
}
.canvas-tool .canvas-tool-item.active{
    border: 1px solid orange;
}