body {font-size: 62.5%}
div1 {width: 60em; /*60* 10=600px*/}
div2 {font-size: 20px; /*此时在div 中 1em= 20px*/}
|
<body>
<div class="div1"></div>
<div class="div2"></div>
</body>
em
body {font-size: 62.5%; color: #000; font-family: "微软雅黑";}
.div1 {height: 3em; background-color: #333; /*由于chrome字体默认是12px, 所以此时height=36px*/}
ul, ol {list-style: none;}
.div2 {font-size: 20px; height: 2em; background-color: #555; /*这里改变了font-size 所以height=40px*/}
rem
html {font-size: 20px; color: #000; font-family: "微软雅黑";}
.div1 {height: 3rem; background-color: #333; /*此时height=60px*/}
ul, ol {list-style: none;}
.div2 {font-size: 20px; height: 2rem; background-color: #555; /*改变font-size不在影响 所以height=40px*/}
|
<html style="font-size:20px;">
<body>
<div style="font-size:10px;">
<div style="font-size:1em;">1em*10=10px</div>
<div style="font-size:1rem;">1rem*20=20px</div>
</div>
</body>
</html>
|
