* {
  box-sizing: border-box;
}

body {
  background-color: #eee;
}

form {
  margin: 0;
}

#container {
  width: 90%;
  max-width: 800px;
  background-color: #fff;
  padding: 1rem;
  margin: 1rem auto;
  border: 1px solid #ccc;
}

.config_select {
  width: 150px;
  display: inline;
  margin-right:10px;
}