404.html

<style lang=scss scoped> 
html, body {
	margin: 0;
	padding: 0;
	height: 100%;
	width: 100%;
  
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  background-color: #f5f5f5;
	color: #4a4a4a;
}

.content {
  font-family: 'Avenir-Next', Avenir, Helvetica, sans-serif;
  background-color: none;
  z-index: 2;
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  text-align: center;
  transform: translateY(-50%);
  padding: 0 10px;
}

h1 {
  font-size: 120px;
  margin-bottom: 0;
  margin-top: 0;
}

h2 {
  margin-top: 0;
  font-size: 30px;
}

p {
  padding-bottom: 32px;
}
img {
  width: 5em;
  height: auto;
}
@media only screen and (max-width: 480px) {
  h1 {
    font-size: 120px;
  }
}
</style>

<div class='container'>
 <div class='row'>
  <div class='content'>
   <img src="http://vtaiwan.tw/vTaiwan_logo_2017.png" alt="logo">
   <h1>Error 404</h1>
   <h2>Oops, the page you're looking for does not exist.</h2>
   <p>
    You may want to head back to the <a href="/">homepage</a>.
   </p>
  </div>
 </div>
</div>