Is Fasting Food Specific?

Questions about whether biblical fasting is food specific or could include things like social media, how the “faith” listed as a gift of the Spirit in 1 Corinthians 12:9 differs from the saving faith given to all believers, and whether it’s biblical for people with a prophetic gift to predict suffering and death.  

• Is it biblical to abstain from something like social media as a form of fasting to pray for a specific thing, or is fasting food specific?
• Is the “faith” listed as a gift of the Spirit in 1 Corinthians 12:9 somehow different from the saving faith given to all believers?
• Is it biblical for people with a prophetic gift to predict seasons of suffering or when a person will die?