仅以编程方式折叠工具栏

<div class="toolbar">
  <button class="toggle-button">折叠</button>
  <button>按钮1</button>
  <button>按钮2</button>
  <button>按钮3</button>
  <button>按钮4</button>
</div>

.toolbar button:not(.toggle-button) {
  display: none;
}

.toolbar.collapsed button:not(.toggle-button) {
  display: inline-block;
}

const toggleButton = document.querySelector('.toggle-button');
const toolbar = document.querySelector('.toolbar');

toggleButton.addEventListener('click', function() {
  toolbar.classList.toggle('collapsed');
});