<h2>按钮颜色</h2> <p>我们可以使用 background-color 属性来设置按钮颜色:</p> <button class="button">Green</button> <button class="button button2">Blue</button> <button class="button button3">Red</button> <button class="button button4">Gray</button> <button class="button button5">Black</button>