npm run gulp watch

I am trying to run the above command. It was running perfect previously but not now I think I did something wrong in npm packages.

Vipins-Air:gulp vipingupta$ npm run gulp watch

> site@1.0.0 gulp /Users/vipingupta/Desktop/Sites/site
> gulp "watch"

module.js:487
    throw err;
    ^

Error: Cannot find module './gulp/tasks/styles'
    at Function.Module._resolveFilename (module.js:485:15)
    at Function.Module._load (module.js:437:25)
    at Module.require (module.js:513:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/Users/vipingupta/Desktop/Sites/site/gulpfile.js:1:63)
    at Module._compile (module.js:569:30)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:503:32)
    at tryModuleLoad (module.js:466:12)
    at Function.Module._load (module.js:458:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! site@1.0.0 gulp: `gulp "watch"`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the site@1.0.0 gulp script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above

via Skumar