html,
body {
  padding: 0;
  font-family: 'Comic Sans MS', "Comic Sans", cursive;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin: auto;
  height: 90%;
}

main {
  height: 100%;
  width: 90%;
  margin: 5px auto;
}

section {
  flex-direction: column;
  display: none;
}

#listbook {
  display: flex;
}

nav {
  height: 50px;
  padding: 0 20px;
  margin-bottom: 10px;
  display: flex;
  justify-content: space-between;
  color: black;
}

ul {
  display: flex;
  list-style: none;
  margin: 5px 0;
  line-height: 44px;
}

li {
  display: inline-block;
  padding: 0 10px;
}

span {
  line-height: 54px;
}

a {
  color: black;
  text-decoration: none;
}

a:active {
  font-weight: bold;
}

h1,
h2 {
  font-size: 24px;
  margin: 0 auto;
  text-align: center;
  color: black;
}

footer {
  position: relative;
  width: 90%;
  margin: auto;
  bottom: 0;
  color: white;
  text-align: start;
}

h3 {
  font-size: 24px;
  margin-left: 0;
  padding: 10px 20px;
  color: black;
  border: solid 3px black;
}

button {
  position: relative;
  font-family: 'Comic Sans MS', "Comic Sans", cursive;
  font-weight: bold;
  background-color: white;
  color: black;
  margin-right: 5px;
  padding: 2px 10px;
  box-shadow: 2px 2px 0 black;
}

input {
  font-family: 'Comic Sans MS', "Comic Sans", cursive;
  font-weight: bold;
  font-size: 14px;
  color: black;
}

p {
  margin: 0;
  font-weight: bold;
  display: flex;
  padding: 3px;
  font-size: 14px;
  line-height: 28px;
  justify-content: space-between;
}

#booklist > p:nth-of-type(odd) { background: gray; }

.border {
  border: solid 3px black;
}

.add {
  position: relative;
  margin-left: 155px;
  font-family: 'Comic Sans MS', "Comic Sans", cursive;
  background-color: white;
  color: black;
  padding: 2px 10px;
  box-shadow: 2px 2px 0 black;
  margin-right: 0;
}

.booklist:empty {
  display: none;
}

.border-right {
  border-right: 1px solid black;
}