数值无法被CSS识别的HTML ID(HTML ID with numerical value not recognized by CSS)

 这是div： 
 
<div class='something' id='1'>
 
 我在页面上的不同位置上获得了9个，因此在.css文件中我做了： 
 
div#1.something {
  code...
}
 
 事情是，它不会工作，我知道这是正确的选择，但我也尝试div.something#1 ，它也不能正常工作。 我认为ID是一个数字有问题，我应该改变它还是有办法？ 

Here is the div:
 
<div class='something' id='1'>
 
I got 9 of them with different positions on page so in the .css file I do:
 
div#1.something {
  code...
}
 
And the thing is that it won't work, I know this is the proper selector but I have also tried div.something#1 and it also doesn't work, as expected. I think there is something wrong with ID as a number, should I change it or there is a way? 

原文：https://stackoverflow.com/questions/36458637