我删除了一些多余的标记（圆形和方形容器……只需要一个）并设置了img本身的样式：
#wrapper { width: 500px; height: 500px; border-radius: 50%; overflow: hidden; -webkit-mask-image: -webkit-radial-gradient(circle, white, black);}#test { width: 100%; height: 100%; transition: all 2s linear;}#test:hover { transform: scale(1.2);}<div id="wrapper"> <img src="http://rack.3.mshcdn.com/media/ZgkyMDEzLzA1LzA4L2JlL2JhYmllc193aXRoLjA5NGNjLnBuZwpwCXRodW1iCTg1MHg1OTA-CmUJanBn/8f195417/e44/babies_with_swagg.jpg" id="test"></div>
