* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
}

body {
  width: 100%;
  font-family: Arial, Helvetica, sans-serif;
  display: grid;
  align-items: center;
  justify-items: center;
  text-align: center;
  background-color: lightgray;
  overflow: hidden;
}

img {
  max-width: 100%;
  max-height:100%;
  display: inline-block;
  margin: 0 auto;
  vertical-align: middle;
}

#navbar, #footer {
  display: block;
  position: absolute;
  padding: 10px 20px;
}

#navbar {
  z-index: 20;
  top: 0;
  left: 0;
  border-radius: 0 0 15px 0;
}

#footer {
  z-index: 5;
  bottom: 0;
  right: 0;
  text-align: right;
  font-size: 11px;
  border-radius: 15px 0 0 0;
}

#navbar h1 {
  margin: 0;
  font-family: 'Cookie', cursive;
  font-size: 35pt;
  color: #000;
  text-shadow: 2px 2px #e8e3c7;
}

#arrows {
  display: block;
  width: 100%;
  z-index: 10;
  position: absolute;
  top: 48%;
}

#arrows a {
  text-decoration: none;
  padding: 30px;
  font-size: 35px;
  font-weight: 900;
  background-color: rgba(169, 169, 169, 0.5);
  color: #fff;
}

#arrows a:focus {
  background-color: rgba(169, 169, 169, 0.5);
  color: #fff;
}

#arrows a:hover {
  color: #000;
  background-color: rgba(169, 169, 169, 1);
}

.pre {
  float: left;
  border-radius: 0 15px 15px 0;
}

.next {
  float: right;
  border-radius: 15px 0 0 15px;
}