How to write a css style so that the background changes only for the first and last button?

Question

css

You need to change the background of all buttons, except for the extreme ones (first and last). How to do it?

<div data-role="buttons">
    <button>1</button>
    <button>2</button>
    <!-- ещё кнопки -->
    <button>8</button>
    <button>9</button>
</div>

Answer 1

button:not(:first-child):not(:last-child)  {
  background: @yourColor;
}

Answer 2

div button {
    background: #f00;
}

div button:first-child {
    background: transparent;
}

div button:last-child {
    background: transparent;
}