body {
  text-align: center;
}

.container {
  width: 1015px;
  margin: 0 auto;
}

.big-area {
  width: 100%;
  height: 800px;

  text-align: center;
  background-color: #f7f7f7;
  position: relative;
}

.big-area div {
  position: absolute;
  font-size: 40px;
  top: 50%;
  left: 50%;
}

.big-area h1, h2, h3 {
  padding: 0;
  margin: 0;
}

.big-area h1 {
  font-size: 70px;
}

.big-area h2 {
  font-size: 16px;
  color: #666;
}

.big-area a {
  font-size: 16px;
  color: blue;
  text-decoration: none;
}

section {
  margin-bottom: 100px;
  width: 100%;
  height: 505px;
  background-color: #f5f5f5;
  position: relative;
}

section .content {
  display: none;
}

section span {
  position: absolute;
  top: 50%;
  display: inline-block;
  margin-left: -32px;
}

section img {
  width: 250px;
  height: 250px;
}

.lazy {
  opacity: 0;
  -moz-transition: opacity 2s;
  -webkit-transition: opacity 2s;
  -o-transition: opacity 2s;
  transition: opacity 2s;
}

.lazy.loaded {
  opacity: 1;
}