:root {
  color-scheme: light;
}

html, body {
  margin: 0;
  padding: 0;
  background: #fff;
  color: #000;
  font-family: Arial, sans-serif;
  font-size: 18px;
  line-height: 1.45;
}

img {
  max-width: 100%;
}

.header {
  border-bottom: 2px solid #000;
  padding: 0.75rem 1rem;
}

.header-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 1.2rem;
}

.header h1 {
  margin: 0;
  font-size: 1.2rem;
  line-height: 1.2;
}

.header a {
  color: inherit;
  text-decoration: none;
}

.header-back {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.5rem;
  height: 1.5rem;
  margin: -0.15rem 0;
  font-size: 1.2rem;
  line-height: 1;
  font-weight: bold;
  flex: 0 0 1.5rem;
}

.container {
  padding: 1rem;
  max-width: 42rem;
}

h2 {
  margin-top: 0;
  font-size: 1.25rem;
}

.page-head {
  margin-bottom: 1rem;
}

.page-subtitle {
  margin: 0.25rem 0 0;
  font-size: 0.95rem;
}

.book-list {
  list-style: none;
  margin: 0 -0.25rem;
  padding: 0;
}

.book-item {
  display: inline-block;
  width: 33.3333%;
  vertical-align: top;
  box-sizing: border-box;
  padding: 0.25rem;
  margin: 0;
  border: none;
}

.book-card {
  display: block;
  border: 1px solid #000;
  padding: 0.5rem;
  color: inherit;
  text-decoration: none;
}

.book-card-cover {
  display: block;
  margin-bottom: 0.5rem;
}

.book-card-body {
  display: block;
}

.book-detail-cover {
  display: block;
}

.book-card-cover,
.book-detail-cover {
  text-align: center;
}

.book-cover,
.book-cover-placeholder {
  display: inline-block;
  width: 100%;
  max-width: 100%;
  aspect-ratio: 2 / 3;
  border: 1px solid #000;
  object-fit: cover;
  vertical-align: top;
}

.book-cover-placeholder {
  text-align: center;
  font-size: 0.75rem;
  font-weight: bold;
  line-height: 1.2;
  padding-top: 2.3rem;
  box-sizing: border-box;
}

.book-cover-detail,
.book-cover-placeholder-detail {
  width: 8rem;
  height: 11.5rem;
  max-width: none;
  margin-bottom: 1rem;
}

.book-title {
  display: block;
  font-weight: bold;
  font-size: 0.95rem;
  line-height: 1.25;
  margin-bottom: 0.25rem;
}

.book-author,
.book-author-detail {
  display: block;
  margin-top: 0.2rem;
}

.book-author {
  font-size: 0.85rem;
  line-height: 1.25;
}

.format {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.85rem;
}

.book-detail {
  display: block;
}

.book-detail-cover {
  margin-bottom: 1rem;
}

.book-meta {
  margin: 0 0 1rem;
}

.book-meta div {
  margin-bottom: 0.6rem;
}

.book-meta dt {
  font-weight: bold;
}

.book-meta dd {
  margin: 0.15rem 0 0;
}

.back-link {
  color: inherit;
}

.btn {
  display: inline-block;
  min-height: 44px;
  padding: 0.7rem 1rem;
  border: 2px solid #000;
  text-decoration: none;
  color: #000;
  font-weight: bold;
}

code {
  border: 1px solid #000;
  padding: 0.1rem 0.3rem;
}

/* --- Auth & Upload --- */

.btn-logout {
  background: none;
  border: 1px solid #000;
  cursor: pointer;
  padding: 0.3rem 0.6rem;
  font-size: 0.9rem;
}

.login-box {
  max-width: 22rem;
  margin-top: 3rem;
}

.login-form,
.upload-form {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.login-form input,
.upload-form input[type="file"] {
  padding: 0.5rem;
  font-size: 1rem;
  border: 1px solid #000;
}

.error {
  border: 2px solid #000;
  padding: 0.5rem 0.75rem;
  margin-bottom: 0.75rem;
  font-weight: bold;
}