Resize images and videos to fill their parent and maintain their aspect ratio with pure CSS. The new object-fit and object-position properties allow you to scale images and videos, much like you could with background-size and background-position.
img { width: 90vw; height: 75vh; border: 3px solid tomato; } .img-con1 img{ object-fit: fill; } .img-con2 img{ object-fit: contain; } .img-con3 img{ object-fit: cover; } .img-con4 img{ object-fit: none; } .img-con5 img{ object-fit: scale-down; } .img-con6 img{ object-fit: fill; object-position: 20px 5px; } /* Demo styles only */ * { box-sizing: border-box; } body { margin: 0; }
[CSS] Control Image Aspect Ratio Using CSS
原文：http://www.cnblogs.com/Answer1215/p/6002203.html