@charset "UTF-8";

body {
  background-color: gray;
  /* background: url(images/bg.jpg) no-repeat;
  background-size: cover;
  background-attachment: fixed; */
} 

body::before {
  content: "";
  background: url(images/bg.jpg) no-repeat;
  background-size: cover;
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  z-index: -1;
}

#wrap {
  width: 960px;
  margin: auto;
  background-color: white;
}

header {
  padding: 40px;
  height: 80px;
}

nav {
  padding: 8px 40px;
  background-color: black;
  color: white;
}

main {
  padding: 40px;
  height: 800px;
}

.mark::before {
  content: "《";
}

.mark::after {
  content: "》";
}

.arrow::before {
  content: "";
  display: inline-block;
  border: 8px solid transparent;
  border-left: 8px solid blue;
}

.download::after {
  content: "Download";
  display: inline-block;
  background-color: darkblue;
  color: white;
  font-weight: bold;
  padding: 2px;
  margin-left: 10px;
  border-radius: 2px;
  font-size: 12px;
}

footer {
  padding: 40px;
  height: 40px;
  background-color: black;
  color: white;
}