设置输入类型="文件"按钮的样式

#file-input {
  display: none;
}

.file-input-button {
  display: inline-block;
  padding: 10px 20px;
  background-color: #4CAF50;
  color: white;
  border: none;
  cursor: pointer;
}

.file-input-button:hover {
  background-color: #3e8e41;
}

const fileInputButton = document.createElement('button');
fileInputButton.className = 'file-input-button';
fileInputButton.innerText = '选择文件';
fileInputButton.addEventListener('click', () => {
  document.getElementById('file-input').click();
});

document.body.appendChild(fileInputButton);