All browsers that support the CSS text-shadow and box-shadow properties also support the new CSS3 RGBa syntax. Which means you can safely combine them today.

Rails Long Term Support

Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)

Prevents you from data breaches and liability risks
Upgrade at your own pace
Works with modern Rubies

mezzoblue § A CSS3 Tip

Rails Long Term Support