.becf-grid {
  display: flex;
  gap: 10px;
  font-family: sans-serif;
}
.becf-left {
  width: 20%;
  background: #ccc;
  padding: 10px;
}
.becf-center {
  width: 45%;
  background: #fff;
  padding: 10px;
}
.becf-right {
  width: 35%;
  background: #ccc;
  padding: 10px;
}
canvas#box3d {
  width: 100%;
  height: 300px;
  background: black;
}
.mockup-box {
  background: #eee;
  border: 1px dashed #888;
  height: 100px;
  margin-top: 10px;
  text-align: center;
  padding-top: 30px;
}
input {
  width: 90%;
  margin-bottom: 10px;
}