摘要： 1rem = 1*根元素font-size px rem与px 场景：图片占位符 1em = 1*相对父类font-size px em与px 1vw = 可视窗口的宽度的1% vw与% 场景：图片占位符 100% 100%/3.5 = 28.57% 1vw = 1% 28.57% = 28.57v 阅读全文