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

body,
input,
button {
  font-family: "Open Sans", sans-serif;
}

input,
button {
  font-family: "Raleway", sans-serif;
  font-size: 18px;
}

.head_bar {
  padding: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: blueviolet;
  color: white;
  font-family: "Montserrat", sans-serif;
}

main {
  position: relative;
  max-width: 800px;
  width: 80%;
  margin: 0 auto;
  padding: 16px;
}

.input_section,
.search_section,
.book_shelf {
  font-family: "Raleway", sans-serif;
}

.input_section {
  display: flex;
  flex-direction: column;
  padding: 16px;
  box-shadow: 0px 10px 30px 10px lightblue;
  border-radius: 10px;
}

.input_section > h2 {
  text-align: center;
  color: cornflowerblue;
  font-family: "Montserrat", sans-serif;
}

.input_section > form > .input {
  position: relative;
  margin: 8px 0;
}

.input_section > form > button {
  background-color: cornflowerblue;
  color: white;
  border: 0;
  border-radius: 5px;
  display: block;
  width: 100%;
  padding: 8px;
  cursor: pointer;
}

.input_section > form > button > span {
  font-weight: bold;
}

.input_section > form > .input > input {
  display: block;
  width: 100%;
  padding: 8px;
  border-radius: 5px;
  margin-top: 8px;
  outline: none;
  border: none;
}

.input_section > form > .input > input:focus ~ .underscore2 {
  width: 100%;
}
.input_section > form > .input > input:focus ~ .underscore1 {
  width: 0%;
}

.input_section > form > .input > label {
  color: cornflowerblue;
  font-weight: bold;
  font-size: 20px;
}

.underscore1 {
  position: absolute;
  width: 100%;
  height: 2px;
  background-color: blueviolet;
  right: 0;
  bottom: 0;
  transition: all 0.8s;
}
.underscore2 {
  position: absolute;
  width: 0%;
  height: 2px;
  background-color: black;
  bottom: 0;
  transition: all 1s;
}

.input_section > form > .input_inline {
  margin: 12px 0;
  display: flex;
  align-items: center;
}

.input_section > form > .input_inline > label {
  color: cornflowerblue;
  font-weight: bold;
  margin-right: 10px;
  font-size: 20px;
}

.input_section > form > .input_inline > input {
  width: 16px;
  height: 16px;
}

.search_section {
  margin: 30px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px;
  box-shadow: 0px 10px 30px 10px lightblue;
  border-radius: 10px;
}

.search_section > h2 {
  color: cornflowerblue;
  font-family: "Montserrat", sans-serif;
}

.search_section > form {
  padding: 16px;
  width: 100%;
  display: grid;
  grid-template-columns: auto 1fr 0.5fr;
  grid-gap: 10px;
}

.search_section > form > label {
  display: flex;
  align-items: center;
  color: cornflowerblue;
  font-weight: bold;
  font-size: 20px;
}

.search_section > form > input {
  padding: 5px;
  border-radius: 5px;
  outline: none;
  border-top: 0;
  border-left: 0;
  border-right: 0;
  border-bottom: 2px solid blueviolet;
}

.search_section > form > button {
  background-color: cornflowerblue;
  color: white;
  border: 0;
  border-radius: 5px;
  cursor: pointer;
}

.book_shelf {
  margin: 26px 0 0 0;
  padding: 16px;
  box-shadow: 0px 10px 30px 10px lightblue;
  border-radius: 10px;
}

.book_shelf > h2 {
  color: cornflowerblue;
  font-family: "Montserrat", sans-serif;
}

.book_shelf > .book_list {
  padding: 16px;
}

.book_shelf > .book_list > .book_item {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  padding: 10px 18px;
  border: 1px solid lightblue;
  box-shadow: 0px 0px 20px lightblue;
  border-radius: 10px;
  margin: 10px 0;
}

.book_shelf > .book_list > .book_item > h3,
p {
  margin: 8px 0;
}

.book_shelf > .book_list > .book_item > .action {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.book_shelf > .book_list > .book_item > .action > button {
  border: 0;
  padding: 5px;
  font-size: 16px;
  border-radius: 5px;
  font-weight: 500;
  cursor: pointer;
}

.green {
  background-color: green;
  color: white;
}

.yellow {
  background-color: yellowgreen;
  color: white;
}

.red {
  background-color: red;
  color: white;
}

.pop-up-modal {
  position: fixed;
  padding: 8px 12px;
  color: white;
  left: 20px;
  top: -100px;
  opacity: 0;
  text-transform: capitalize;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
  border-radius: 10px;
  text-align: center;
  transition: top ease-in-out 0.3s, opacity ease-in-out 0.3s;
}

.pop-up-modal h3 {
  padding: 6px;
}

.pop-up-modal p {
  font-size: 14px;
  margin-bottom: 6px;
}

.pop-up-modal.delete-todo {
  background-color: red;
}

.pop-up-modal.display {
  top: 20px;
  opacity: 1;
}

@media only screen and (max-width: 600px) {
  .search_section > form {
    display: flex;
    flex-direction: column;

  }

  .search_section > form > button {
    padding: 4px;
  }
}