<!DOCTYPE html>
<html>

  <head>
    <script data-require="jquery@*" data-semver="2.1.3" src="http://code.jquery.com/jquery-2.1.3.min.js"></script>
    <link href="//cdn.muicss.com/mui-0.0.3/css/mui.min.css" rel="stylesheet" type="text/css" />
    <link rel="stylesheet" href="style.css" />
  </head>

  <body id="app">
    <header class="header" v-class="sticky: position > 0">
      sushicorp
    </header>
    <p v-show="position > 0">No.1 Enterprise Sushi Corporation</p>
    <div class="mui-container container">
      <div class="mui-panel">
        <h3>First</h3>

        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        <h3>Second</h3>

        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        <h3>Third</h3>

        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
      <div class="mui-panel">
        Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ratione, autem, animi, itaque, ipsum dolore quaerat harum voluptate et porro officiis dicta consequatur explicabo numquam quas aliquam aperiam ab error est.
      </div>
    </div>
    <div class="toTop" v-if="position > 500" v-on="click: toTop()" v-transition>
      Jump To Top
    </div>
    <script data-require="vue.js@*" data-semver="0.11.5" src="http://cdnjs.cloudflare.com/ajax/libs/vue/0.11.5/vue.min.js"></script>
    <script src="script.js"></script>
  </body>

</html>
// Code goes here

new Vue({
  el: "#app",
  data: {
    position: 0
  },
  methods:{
    toTop: function(){
      //やむなくjQuery
      $("html,body").animate({scrollTop:0},"slow");
    }
  },
  ready: function(){
    var self = this;
    document.onscroll = function(e){
      self.position = document.documentElement.scrollTop || document.body.scrollTop;
    }
  }
});
/* Styles go here */

.small{
  font-size: 1rem;
}

.container{
  padding-top: 12rem;
}

header{
  text-align: center;
  position: fixed;
  width: 100%;
  color: #888;
  background: white;
  text-shadow: 0px 1px 2px #777;
  color: white;

  font-size: 5rem;
  height: 10rem;
  line-height: 10rem;
  transition: all 0.3s ease;
  background-image: url(http://cdn.backgroundhost.com/backgrounds/subtlepatterns/greyfloral.png);
}

.sticky {
  background: rgba(200,200,200, 0.5);
  text-align: left;
  text-shadow: 0px 1px 2px #777;
  color: white;
  font-size: 2rem;
  padding-left: 10px;
  height: 4rem; 
  line-height: 4rem;
}

.toTop{
  position: fixed;
  right: 0;
  bottom:0;
  height: 3rem;
  line-height: 3rem;
  color: white;
  text-align: center;
  width: 100px;
  cursor: pointer;
  transition: all .3s ease;
  background: black;
}

.toTop.v-enter, .toTop.v-leave {
  height: 0;
  padding: 0 10px;
  opacity: 0;
}
#アニメーションするヘッダ、トップへ戻るボタンをVueでやる

 * トップへスムーススクロールする部分だけはやむなくjQuery使ってます。