Install ESP8266 into platformio IDE

I did “platformio lib install 1101” (PlatformIO Registry),
I installed this: PlatformIO Registry (follow instructions)
I did similar things to other libraries.

When I click the platformio:build button, it still complains:

fatal error: ESP8266WiFi.h: No such file or directory
fatal error: ESP8266WiFiMulti.h: No such file or directory
fatal error: ESP8266Webserver.h: No such file or directory

Did you include these libraries in the project? Could you share here your project?

I took out all the code, then put them back one by one and compiling at the same time. It is tedious, but it seems work. Will keep you update.