style.css

ul li {
  list-style-type: none;
  line-height: 0;
}

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

.active {
  color: blue;
}

.header {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  border: 3px solid black;
  padding: 5px;
  height: 50px;
}

.header-title {
  font-size: 18px;
}

.header-menu {
  display: flex;
  margin-right: 5px;
  gap: 10px;
  background-color: black;
}

.header-items {
  font-weight: bold;
  font-size: 12px;
}

.bar {
  border-right: 0.3em solid black;
  padding-right: 5px;
}

header ul li {
  cursor: pointer;
  list-style: none;
}

main {
  height: 80vh;
}

#date {
  display: flex;
  justify-content: flex-end;
  margin-top: 10px;
  font-weight: bold;
  font-size: 12px;
}

.booklist-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 30px;
}

.booklist-container ul li {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding: 5px;
}

.booklist-border {
  border: 3px solid black;
}

.list-border {
  display: flex;
  flex-direction: column;
  width: 80%;
  padding-left: 0;
}

.book-info {
  display: flex;
  align-items: center;
  flex-direction: row;
  gap: 5px;
  width: 100%;
}

li button {
  border: 3px solid black;
  box-shadow: 3px 3px;
  margin-top: 5px;
}

ul li:nth-child(odd) {
  background-color: rgba(128, 128, 128, 0.5);
}

.book-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 80px;
}

form {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.form-books {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: flex-end;
}

#add-book {
  border: 3px solid black;
  box-shadow: 3px 3px;
}

form input {
  border: 3px solid black;
  width: 180px;
}

.error-msg {
  color: red;
}

.contact-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 80px;
  padding: 0 15px;
}

.contact-container ul li {
  list-style: disc;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 25px;
}

.hide {
  display: none;
}

.footer {
  border: 3px solid black;
  padding: 5px 5px;
  height: 50px;
}

.footer p {
  font-weight: bold;
  margin-top: 0;
}

.footer a {
  color: blue;
}

@media screen and (min-width: 768px) {
  .header {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    border: 3px solid black;
    padding: 5px;
    height: 50px;
  }

  .header-title {
    margin-left: 20px;
    font-size: 22px;
  }

  .header-menu {
    display: flex;
    margin-right: 50px;
    gap: 50px;
    background-color: black;
  }

  .header-items {
    font-weight: bold;
    font-size: 18px;
  }

  .bar {
    border-right: 0.3em solid black;
    padding-right: 41px;
  }

  header ul li {
    cursor: pointer;
    list-style: none;
  }

  #date {
    display: flex;
    justify-content: flex-end;
    margin-top: 10px;
    font-weight: bold;
    font-size: 18px;
  }

  .booklist-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 30px;
  }

  .booklist-container ul li {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 5px;
  }

  .booklist-border {
    border: 3px solid black;
  }

  .list-border {
    display: flex;
    flex-direction: column;
    width: 50%;
    padding-left: 0;
  }

  .book-info {
    display: flex;
    align-items: center;
    flex-direction: row;
    gap: 5px;
    width: 100%;
  }

  li button {
    border: 3px solid black;
    box-shadow: 3px 3px;
    margin-top: 5px;
  }

  ul li:nth-child(odd) {
    background-color: rgba(128, 128, 128, 0.5);
  }

  .book-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 80px;
  }

  form {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .form-books {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: flex-end;
  }

  #add-book {
    border: 3px solid black;
    box-shadow: 3px 3px;
  }

  form input {
    border: 3px solid black;
    width: 180px;
  }

  .error-msg {
    color: red;
  }

  .contact-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 80px;
  }

  .contact-container ul li {
    list-style: disc;
  }

  .contact-details {
    display: flex;
    flex-direction: column;
    gap: 25px;
  }

  .hide {
    display: none;
  }
}