body{
  font-family: Arial;
  background:#f5f5f5;
  margin:0;
  padding:10px;
  text-align:center;
}

.box{
  background:white;
  padding:15px;
  border-radius:12px;
  max-width:700px;
  margin:auto;
  box-shadow:0 10px 30px rgba(0,0,0,.1);
}

#dropZone{
  border:2px dashed #aaa;
  padding:15px;
  margin-top:10px;
}

canvas{
  margin-top:15px;
  border:1px solid #ddd;
  max-width:100%;
}

.controls{
  margin-top:10px;
}

input, select{
  margin:5px;
}

button{
  margin:5px;
  padding:10px;
  border:none;
  border-radius:6px;
  background:#444;
  color:white;
}

/* 📱 mobile */
@media(max-width:600px){
  canvas{
    width:100%;
    height:auto;
  }
}