​x
 
<!DOCTYPE html>
<html>
<head>
<style>
:root {
  --main-bg-color: coral;  
}
​
#div1 {
  background-color: var(--main-bg-color);
  padding: 5px;  
}
​
#div2 {
  background-color: var(--main-bg-color);
  padding: 5px;
}
​
#div3 {
  background-color: var(--main-bg-color);
  padding: 5px;
}
</style>
</head>
<body>
​
<h1>var() 函数</h1>
​
<div id="div1">Shanghai is one of the four direct-administered municipalities of the People's Republic of China. Welcome to Shanghai!</div>
<br>
​
<div id="div2">Shanghai is one of the four direct-administered municipalities of the People's Republic of China. Welcome to Shanghai!</div>
<br>
​
<div id="div3">Shanghai is one of the four direct-administered municipalities of the People's Republic of China. Welcome to Shanghai!</div>
​
</body>
</html>
​