.page-enter-active,.page-leave-active{
 transition: opacity 2s;
}
.page-enter,.page-leave-active{
 opacity: 0;
}

module.exports = {
 /*
 ** Headers of the page
 */
 head: {
 title: 'delnuxt',
 meta: [
  { charset: 'utf-8' },
  { name: 'viewport', content: 'width=device-width, initial-scale=1' },
  { hid: 'description', name: 'description', content: 'Nuxt.js project' }
 ],
 link: [
  { rel: 'icon', type: 'image/x-icon', href: '/favicon.ico' }
 ],
 },
 css:['~assets/css/normailze.css','~assets/css/main.css'],
 /*
 ** Customize the progress bar color
 */
 loading: { color: '#3B8070' },
 /*
 ** Build configuration
 */
 build: {
 /*
 ** Run ESLint on save
 */
 extend (config, { isDev, isClient }) {
  if (isDev && isClient) {
  config.module.rules.push({
   enforce: 'pre',
   test: /\.(js|vue)$/,
   loader: 'eslint-loader',
   exclude: /(node_modules)/
  })
  }
 }
 }
}

.test-enter-active,.test-leave-active{
 transition: all 2s;
 font-size: 12px;
}
.test-enter,.test-leave-active{
 opacity: 0;
 font-size: 40px;
}

<script>
export default {
 transition:'test'
}
</script>

> nuxt-temp@1.0.0 dev E:\MaYunProject\nuxt-temp
> nuxt

E:\MaYunProject\nuxt-temp\node_modules\nuxt\dist\nuxt.js:79
async function promiseFinally(fn, finalFn) {
  ^^^^^^^^

SyntaxError: Unexpected token function
 at createScript (vm.js:56:10)
 at Object.runInThisContext (vm.js:97:10)
 at Module._compile (module.js:542:28)
 at Object.Module._extensions..js (module.js:579:10)
 at Module.load (module.js:487:32)
 at tryModuleLoad (module.js:446:12)
 at Function.Module._load (module.js:438:3)
 at Module.require (module.js:497:17)
 at require (internal/module.js:20:19)
 at Object.<anonymous> (E:\MaYunProject\nuxt-temp\node_modules\nuxt\index.js:17:20)

npm ERR! Windows_NT 10.0.14393
npm ERR! argv "G:\\node\\node.exe" "G:\\node\\node_modules\\npm\\bin\\npm-cli.js" "run" "dev"
npm ERR! node v6.11.4
npm ERR! npm v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! nuxt-temp@1.0.0 dev: `nuxt`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the nuxt-temp@1.0.0 dev script 'nuxt'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the nuxt-temp package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!  nuxt
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!  npm bugs nuxt-temp
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!  npm owner ls nuxt-temp
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!  E:\MaYunProject\nuxt-temp\npm-debug.log

  ERROR Failed to compile with 1 errors
  Module build failed (from ./node_modules/eslint-loader/index.js):
  TypeError: Cannot read property 'eslint' of undefined
   at Object.module.exports (.../node_modules/eslint-loader/index.js:148:18)

  You may use special comments to disable some warnings.
  Use // eslint-disable-next-line to ignore the next line.
  Use /* eslint-disable */ to ignore all warnings in a file.

  - module.exports = {
  + export default {
   // ...
   build: {
    /*
    ** Run ESLint on save
    */
   - extend (config, { isDev, isClient }) {
   -  if (isDev && isClient) {
   + extend (config, { isDev }) {
   +  if (isDev && process.client) {
     config.module.rules.push({
     enforce: 'pre',
     test: /\.(js|vue)$/,
     loader: 'eslint-loader',
     exclude: /(node_modules)/
     })
    }
    }
   }
  }