$fn=60;

include <BOSL2/std.scad>

box_width=150;
box_length=100;
box_height=60;
e=3;
rd=1.5;

module box() {
    rect_tube(size=[box_width, box_length], wall=3, h=box_height, rounding=1.5, anchor=BOT);
    cuboid([box_width, box_length, e], rounding=rd);
}

difference() {
    box();
    translate([0,box_length/2-e/2,box_height*3/4]) cuboid([box_width/3, e*2, box_height/2+e/2], rounding=-box_width/10, edges=[TOP], except=[FRONT,BACK]);
translate([0,box_length/2-e/2,box_height/4+e]) cuboid([box_width/3, e*2, box_height/2], rounding=box_width/10, edges=[BOT], except=[FRONT,BACK]);
}