如何在Opera10.0及更早版本中隐藏CSS?

这里有一个答案:

Future proof CSS hack for LTE Opera 10

此代码仅适用于Opera>=9.5和<10.50:

@media all and (resolution = 0dpi) { // exclude Opera 10.50 and higher
  :root #box { // you need to append :root to all selectors to exclude Opera lt 9.5
    background: #f00;
  }
}