*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: #fff;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", "Noto Sans", "Liberation Sans", Arial, sans-serif;
  font-size: 1rem;
  height: 100vh;
}

.container {
  position: relative;
  overflow: auto;
  color: #fefefe;
  width: 100%;
  max-width: 768px;
  height: 100vh;
  margin: 0 auto;
  background-image: url(../images/bg.jpg);
  background-size: cover;
  background-position: center center;
}

.inner {
  min-height: 100%;
  margin: 10% 5%;
}

.tab {
  margin: 0 auto;
  transition: 250ms ease;
  padding-left: 5px;
}

.tab ul {
  display: flex;
  flex-direction: row-reverse;
  list-style: none;
  margin: 0;
  padding: 0;
}

.tab ul li {
  padding: 5px 15px;
}

.tab ul li img {
  width: 100%;
}

.content {
  position: relative;
  width: 100%;
  min-height: 400px;
  padding: 6%;
  background-color: rgba(255, 255, 255, 0.4);
}

.page {
  padding: 30px 40px 20px;
}

.page img {
  max-width: 100%;
}

.page.hidden {
  display: none;
}

.download-button {
  display: block;
  width: 300px;
  max-width: 80%;
  margin: 0 auto;
  margin-top: 50px;
  position:relative;
}

footer {
  position: sticky;
  bottom: 0;
  left: 0;
  right: 0;
  background: #222;
  color: #f0f0f0;
  text-align: center;
  padding: 4px 10px;
  font-size: 0.9em;
}

footer a {
  color: #f0f0f0;
  text-decoration: none;
}