.filter {
  position: relative;
  display: inline-block;
}

.filter-select {
  padding: 0.5rem;
  font-size: 1rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  background-color: #fff;
  appearance: none;
}

.filter-select:focus {
  outline: none;
  border-color: #007bff;
  box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}