For example, in the background picture of this chapter, there are many icons in the picture. I only want the first icon. How can I make an icon larger? The width and height of this icon are only 30px*30px. I have css Write like this: background: url (../images/xxx.png); background-position: 0px -30px; padding: 40px; width: 40px height: 40px;. But the icon is still only as big as it was originally and will not change as the width and height change

Please help me!