:host {
  display: block;
}

button {
  display: flex;
  align-items: center;
  width: 100%;
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
}

button:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 2px;
}

button::after {
  content: '';
  width: 0.5rem;
  height: 0.5rem;
  margin-left: auto;
  flex-shrink: 0;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
}

button[aria-expanded='true']::after {
  transform: rotate(-135deg);
}