1、图片铺满
background: rgba(12, 100, 129, 1) url('https://images.cnblogs.com/cnblogs_com/yukarin/1639008/o_200129185430DjhScdhUYAA1).png') fixed no-repeat;
background-size:cover //cover是自适应铺满，contain，按比例调整背景图片
.png')){kind=link}
2、img等比例，不设置宽高就会自动比例缩放
<img src="https://images.cnblogs.com/cnblogs_com/yukarin/1639008/o_200129105929%E7%B4%AB%E5%A6%B963296370_p0.jpg" width="325px" center >
![https://images.cnblogs.com/cnblogs_com/yukarin/1639008/o_200129105929%E7%B4%AB%E5%A6%B963296370_p0.jpg"](https://images.cnblogs.com/cnblogs_com/yukarin/1639008/o_200129105929%E7%B4%AB%E5%A6%B963296370_p0.jpg"){kind=link}
3、margin: 10px 15px 10px 15px，分别表示上外边距、右外边距、下外边距、左外边距