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

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

input,
button {
  font-size: 16px;
}

.head_bar {

  display: flex;
  align-items: center;
  justify-content: center;
  background-color: cornflowerblue;
  color: white;
}

main {
  width: 90%;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  flex-direction: row;
}

.content {
  flex-basis: 80%;
  padding: 0.2rem;
}

.input_section {
  display: flex;
  flex-direction: column;
  padding: 1rem;

  border: 1px solid black;
  border-radius: 10px;
  max-height: 60vh;
  position: sticky;
  top: 10vh;
}

.input_section > h2 {
  text-align: center;
  color: cornflowerblue;
}

.input_section > form > .input {
  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;
}


label {
  color: cornflowerblue;
  font-weight: bold;
}


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

label {
  color: cornflowerblue;
  font-weight: bold;
  margin-right: 10px;
}

.search_section {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;

  text-align: center;
  padding: 16px;
  border: 1px solid black;
  border-radius: 1px 1px 10px 10px;
  background-color: white;
}

.search_section > h3 {
  color: cornflowerblue;
}

.search_section > form {
  padding: 16px;
  width: 100%;

  display: flex;
  flex-direction: row;
  justify-content: space-between;
}

.search_section > form > label {
  display: flex;
  align-items: center;
}

.search_section > form > input {
  padding: 5px;
  border-radius: 5px;
  flex-basis: 70%;
}

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

.book_list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}
.book_item {
  max-width: 350px;
  margin: 0.2rem;

}

.book_shelf {
  margin: 16px 0 0 0;
  border: 1px solid black;
  padding: 16px;
  border-radius: 10px;
}

.book_shelf > h2 {
  color: cornflowerblue;
}

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

.book_shelf > .book_list > .book_item {
  padding: 8px 16px 16px 16px;
  border: 1px solid black;
  border-radius: 5px;
}

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

button {
  border: 0;
  padding: 5px;
  margin: 0 5px 0 0;
  border-radius: 5px;
  cursor: pointer;
}

.green {
  background-color: darkgreen;
  color: white;
}
.yellow {
  background-color: gold;
  color: white;
}
.red {
  background-color: darkred;
  color: white;
}
@media screen and (max-width: 850px) {
  main {
    flex-direction: column;
    flex-wrap: wrap;
    padding: 0;
    margin: 0;
    width: 100%;
  }
  .input_section {
    position: initial;
  }
  .search_section {
    padding: 0;
  }
}