index.css

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Comic Sans MS', 'Comic Sans', sans-serif;
}

.btn {
  font-family: 'Comic Sans MS', 'Comic Sans', sans-serif;
  background-color: white;
  border-radius: 5px;
}

.btn:hover {
  background-color: rgb(235, 235, 235);
}

.d-flex {
  display: flex;
}

.col {
  flex-direction: column;
}

.row {
  flex-direction: row;
}

ul {
  list-style: none;
}

#header {
  width: 96%;
  justify-content: space-between;
  padding: 10px 20px;
  border: 2px solid black;
  margin: 5px auto;
}

#header img {
  width: 8%;
  height: auto;
}

#nav-list {
  justify-content: center;
  align-items: center;
}

.nav-item {
  padding: 0 8px;
  text-align: center;
}

.nav-item + .nav-item {
  border-left: 2px solid black;
}

.nav-item a:hover {
  color: blue;
}

.active {
  color: red;
}

.date-time {
  position: absolute;
  top: 55px;
  right: 28px;
}

#main {
  min-height: calc(100vh - 110px);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 15%;
  text-align: center;
}

#main h1 {
  padding-bottom: 15px;
}

#list {
  width: 100%;
  padding-top: 30px;
}

.books-container {
  width: 100%;
  display: flex;
  margin: 18px 0;
  flex-direction: column;
  border: solid 3px darkgray;
}

.book {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 3px 7px;
  font-weight: bold;
}

.book:nth-child(even) {
  background-color: rgb(235, 235, 235);
}

.book:first-child {
  padding-top: 7px;
}

.book:last-child {
  padding-bottom: 7px;
}

.btn-remove {
  align-self: flex-end;
  padding: 3px 7px;
  border: 1px solid red;
  box-shadow: 3px 3px 0 0 #7c7c7c;
  color: red;
}

.clickeable {
  cursor: pointer;
}

#add {
  padding-top: 30px;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

#create-form {
  display: flex;
  flex-direction: column;
  width: 90%;
  gap: 20px;
}

#create-form input {
  font-size: 20px;
  font-family: 'Comic Sans MS', 'Comic Sans', sans-serif;
  padding: 1px 1px;
}

#contact {
  padding-top: 30px;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  text-align: left;
}

#contact ul {
  padding-left: 40px;
  list-style: disc;
}

#form-button {
  font-size: 20px;
  align-self: flex-end;
  padding: 3px 7px;
  border: 1px solid rgb(0, 168, 0);
  box-shadow: 3px 3px 0 0 #7c7c7c;
}

#success-msg {
  color: rgb(0, 219, 0);
}

.divisor {
  width: 30%;
  margin-bottom: 12px;
  border: none;
  border-bottom: 2px solid darkgray;
}

#footer {
  position: relative;
  bottom: 0;
  width: 96%;
  padding: 10px 20px;
  border: 2px solid black;
  margin: 5px auto;
}

.d-off {
  display: none;
}

@media screen and (max-width: 400px) {
  #header {
    justify-content: center;
  }

  #logo {
    display: none;
  }

  #main h1 {
    margin-top: 20px;
  }

  #contact .section-title {
    text-align: center;
  }
}