問題：
backdrop-filter is a recent CSS feature, that is not yet available in modern browsers (at least as of July 1, 2016). backdrop-filter是最新的 CSS 功能，在現代瀏覽器中尚不可用（至少截至 2016 年 7 月 1 日）。
- Chrome 51 supports
backdrop-filtervia Experimental Web Platform flag. Chrome 51 通過實驗網絡平臺標誌支持backdrop-filter。 - Safari 9.1 supports it with
-webkit-prefix Safari 9.1 支持-webkit-前綴 - Firefox 47 have no support Firefox 47 不支持
Being in such an unusable state, I would like to know whether there exists any alternative way to bring in the same result.處於這種無法使用的狀態，我想知道是否有其他方法可以帶來相同的結果。
JS workarounds for blur , grayscale ,… are also welcome也歡迎使用用於blur 、 grayscale JS 解決方法
The development of backdrop-filter can be tracked through https://bugs.chromium.org/p/chromium/issues/detail?id=497522可以通過https://bugs.chromium.org/p/chromium/issues/detail?id=497522跟蹤backdrop-filter的發展