* {
  box-sizing: border-box;
}
*:before, *:after {
  box-sizing: inherit;
}
body, html {
  height: 100%;
  overflow: hidden;
}
body, ul {
  margin: 0;
  padding: 0;
}
body {
  color: #4d4d4d;
  font: 14px/1.4em 'Helvetica Neue', Helvetica, 'Microsoft Yahei', Arial, sans-serif;
  background: #f5f5f5 url('../img/bg.jpg') no-repeat center;
  background-size: cover;
  font-smoothing: antialiased;
}
ul {
  list-style: none;
}