header {
  padding: 10px;
  border-bottom: 1px solid #ccc;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
  -webkit-box-pack: justify;
      -ms-flex-pack: justify;
          justify-content: space-between;
}

header > h1,
header > h2 {
  font-size: 20px;
}

/* div#main-slider */
div#main-slider {
  height: 200px;
}

div#main-slider ul {
  position: relative;
  width: 100%;
  height: 200px;
}

div#main-slider ul li {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 200px;
}

div#main-slider ul li div.main-slide-item {
  height: 200px;
  background-color: gray;
}

div#main-slider ul li div.main-slide-item img {
  width: 100%;
  height: 100%;
  -o-object-fit: cover;
     object-fit: cover;
}

ul.book-list {
  width: 100vw;
  overflow: hidden;
  overflow-x: auto;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
}

ul.book-list > li.book-list-item {
  width: 150px;
  height: 280px;
  background-color: #fff;
}

ul.book-list > li.book-list-item + li {
  margin-left: 10px;
}

ul.book-list > li.book-list-item > div.book-cover > img {
  width: 150px;
  height: 150px;
  -o-object-fit: contain;
     object-fit: contain;
}

ul.book-list > li.book-list-item > div {
  padding: 10px;
}

ul.book-list > li.book-list-item > div h3,
ul.book-list > li.book-list-item > div h4 {
  text-align: center;
}

ul.book-list > li.book-list-item > div h3 {
  font-size: 16px;
}

ul.book-list > li.book-list-item > div h4 {
  font-size: 14px;
}

ul.book-list > li.book-list-item > button {
  display: block;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background-color: #999;
}