非标
此特征是非标准的，且不在标准轨道中。不要在面向 Web 的生产站点中使用它：它不适用于每个用户。实现之间可能存在大的不兼容性，且行为将来可能改变。
-moz-maemo-classic
Gecko-only
CSS
media feature
can be used to apply styles based on whether the user agent is using the original Maemo theme.
<integer>
If the user agent is using Maemo with the original theme, this is 1. If it's using the newer Fremantle theme, this is 0.
Media:
media/visual
Accepts min/max prefixes:
no
:-moz-system-metric(maemo-classic)
CSS
pseudo-class
.