style.css

html {
 font-family: '', sans-serif;
 background-color: #f9f9f9 !important;
}

.prose {
 background-color: rgb(255, 255, 255);
}

.container {
 margin-left: 10px;
 margin-right: 10px;
}

.books {
 display: flex;
 flex-wrap: wrap;
 margin: 1rem;
 justify-content: center;
}

.book {
 width: 30%;
 height: 10rem;
 border: none;
 border-radius: 10%;
 margin: 1rem;
}

.book-title {
 font-size: 1.2rem;
 font-weight: bold;
}

.book-author {
 font-size: 0.8rem;
}

.book-genre {
 font-size: 0.8rem;
}

.book input {
 width: 100%;
 height: 2.5rem;
 padding-left: 0.5rem;
 padding-right: 0.5rem;
 margin-bottom: 0.5rem;
}

button {
 position: absolute;
 bottom: 1rem;
 right: 1rem;
 z-index: 1;
 border: none;
 cursor: pointer;
 outline: none;
 padding: 1rem;
 background-color: #4caf50;
 color: #fff;
 font-size: 1rem;
 text-transform: uppercase;
 border-radius: 50px;
 height: 3rem;
 transition: background-color 0.3s ease;
}

button:hover {
 background-color: #4cb550;
}

.book {
 background-color: rgb(255, 255, 255);
}

.book.selected {
 box-shadow: 0 0 0 2px #4caf50;
}