By default, VSCode will try to guess your indentation options depending on the file you open.
You can customize this easily in File > Preferences > User Settings with:
// Controls the rendering size of tabs in characters. // If set to auto, the value will be guessed based on the opened file. "editor.tabSize": 4, // Controls if the editor will insert spaces for tabs. // If set to auto, the value will be guessed based on the opened file. "editor.insertSpaces": false