:root {
  --bg: #FFFFFF;
  --surface: #F8F9FA;
  --surface-2: #F0F4F9;
  --text: #1F1F1F;
  --text-2: #444746;
  --text-3: #747775;
  --divider: #E1E3E1;
  --outline: #C4C7C5;
  --primary: #0B57D0;
  --primary-container: #D3E3FD;
  --on-primary-container: #041E49;
  --danger: #B3261E;

  --g-blue: #4285F4;
  --g-red: #EA4335;
  --g-yellow: #FBBC04;
  --g-green: #34A853;

  --shadow-1: 0 1px 2px 0 rgba(60, 64, 67, .3), 0 1px 3px 1px rgba(60, 64, 67, .15);
  --shadow-2: 0 1px 2px 0 rgba(60, 64, 67, .3), 0 2px 6px 2px rgba(60, 64, 67, .15);

  --s1: 4px;
  --s2: 8px;
  --s3: 12px;
  --s4: 16px;
  --s5: 24px;
  --s6: 32px;

  --t1: 12px;
  --t2: 14px;
  --t3: 16px;
  --t4: 22px;
  --t5: 28px;

  --bar-h: 64px;
  --nav-h: 64px;
  --duration: 180ms;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) {
    --bg: #1B1B1B;
    --surface: #282A2C;
    --surface-2: #303134;
    --text: #E3E3E3;
    --text-2: #C4C7C5;
    --text-3: #8E918F;
    --divider: #333438;
    --outline: #444746;
    --primary: #A8C7FA;
    --primary-container: #0842A0;
    --on-primary-container: #D3E3FD;
    --danger: #F2B8B5;
    --shadow-1: 0 1px 2px 0 rgba(0, 0, 0, .4), 0 1px 3px 1px rgba(0, 0, 0, .25);
    --shadow-2: 0 1px 2px 0 rgba(0, 0, 0, .4), 0 2px 6px 2px rgba(0, 0, 0, .25);
    color-scheme: dark;
  }
}

html[data-theme="dark"] {
  --bg: #1B1B1B;
  --surface: #282A2C;
  --surface-2: #303134;
  --text: #E3E3E3;
  --text-2: #C4C7C5;
  --text-3: #8E918F;
  --divider: #333438;
  --outline: #444746;
  --primary: #A8C7FA;
  --primary-container: #0842A0;
  --on-primary-container: #D3E3FD;
  --danger: #F2B8B5;
  --shadow-1: 0 1px 2px 0 rgba(0, 0, 0, .4), 0 1px 3px 1px rgba(0, 0, 0, .25);
  --shadow-2: 0 1px 2px 0 rgba(0, 0, 0, .4), 0 2px 6px 2px rgba(0, 0, 0, .25);
  color-scheme: dark;
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Roboto, -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Yu Gothic UI", "Noto Sans JP", sans-serif;
  font-size: var(--t2);
  line-height: 1.7;
  overscroll-behavior-y: none;
  -webkit-font-smoothing: antialiased;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}

svg {
  display: block;
  fill: currentColor;
}

input,
textarea,
select {
  font: inherit;
  font-size: max(16px, var(--t2));
  color: var(--text);
  background: var(--surface);
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 14px var(--s4);
  width: 100%;
  transition: border-color var(--duration) ease, background var(--duration) ease;
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--primary);
  background: var(--bg);
}

textarea {
  line-height: 1.9;
  resize: vertical;
}

/* --- App bar --- */

.bar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--s2);
  height: var(--bar-h);
  padding: 0 var(--s2);
  padding-top: env(safe-area-inset-top);
  background: var(--bg);
}

.bar__title-group {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: var(--s2);
}

.bar__title {
  min-width: 0;
  margin: 0;
  padding: 0 var(--s2);
  font-size: var(--t4);
  font-weight: 400;
  line-height: 1.3;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.bar__icon {
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  border-radius: 22%;
  margin-left: var(--s2);
}

.icon-btn {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  border-radius: 20px;
  display: grid;
  place-items: center;
  color: var(--text-2);
  transition: background var(--duration) ease;
}

.icon-btn:active {
  background: var(--surface-2);
}

/* しばらくバックアップしていないときの通知ドット */
.icon-btn--dot {
  position: relative;
}

.icon-btn--dot::after {
  content: "";
  position: absolute;
  top: 8px;
  right: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--g-red);
  box-shadow: 0 0 0 2px var(--bg);
}

.text-btn {
  flex: 0 0 auto;
  height: 40px;
  padding: 0 var(--s3);
  border-radius: 20px;
  color: var(--primary);
  font-size: var(--t2);
  font-weight: 500;
  letter-spacing: .1px;
  transition: background var(--duration) ease;
}

.text-btn:active {
  background: var(--surface-2);
}

.text-btn:disabled {
  color: var(--text-3);
}

main {
  padding: 0 var(--s4);
  padding-bottom: calc(120px + env(safe-area-inset-bottom));
  max-width: 720px;
  margin: 0 auto;
}

/* --- Bottom navigation --- */

.nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 15;
  display: flex;
  justify-content: center;
  gap: var(--s6);
  height: calc(var(--nav-h) + env(safe-area-inset-bottom));
  padding-bottom: env(safe-area-inset-bottom);
  background: var(--surface);
}

.nav__item {
  flex: 0 0 auto;
  width: 88px;
  padding-top: 10px;
  display: grid;
  justify-items: center;
  gap: 3px;
  color: var(--text-2);
}

.nav__pill {
  width: 60px;
  height: 30px;
  border-radius: 15px;
  display: grid;
  place-items: center;
  transition: background var(--duration) ease;
}

.nav__item[aria-selected="true"] .nav__pill {
  background: var(--primary-container);
  color: var(--on-primary-container);
}

.nav__label {
  font-size: var(--t1);
  font-weight: 500;
  letter-spacing: .3px;
}

.nav__item[aria-selected="true"] .nav__label {
  color: var(--text);
}

/* --- Shelf grid --- */

.shelf {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--s5) var(--s3);
  padding-top: var(--s2);
}

@media (min-width: 560px) {
  .shelf {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.book {
  display: block;
  align-self: start;
  text-align: left;
  animation: rise var(--duration) ease both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: none; }
}

.book__cover {
  position: relative;
  aspect-ratio: 2 / 3;
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow-1);
  transition: transform var(--duration) ease;
}

.book:active .book__cover {
  transform: scale(.97);
}

.book__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.book__placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: flex-start;
  padding: var(--s3) 10px;
  font-size: var(--t1);
  font-weight: 500;
  line-height: 1.6;
  overflow: hidden;
  word-break: break-word;
}

.ph-0 { background: #E8F0FE; color: #1967D2; }
.ph-1 { background: #FCE8E6; color: #C5221F; }
.ph-2 { background: #FEF7E0; color: #B06000; }
.ph-3 { background: #E6F4EA; color: #137333; }

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .ph-0 { background: #1F3050; color: #A8C7FA; }
  html:not([data-theme="light"]) .ph-1 { background: #4A2523; color: #F2B8B5; }
  html:not([data-theme="light"]) .ph-2 { background: #453620; color: #FDD663; }
  html:not([data-theme="light"]) .ph-3 { background: #1F3D2A; color: #81C995; }
}

html[data-theme="dark"] .ph-0 { background: #1F3050; color: #A8C7FA; }
html[data-theme="dark"] .ph-1 { background: #4A2523; color: #F2B8B5; }
html[data-theme="dark"] .ph-2 { background: #453620; color: #FDD663; }
html[data-theme="dark"] .ph-3 { background: #1F3D2A; color: #81C995; }

.book__title {
  margin: 10px 0 0;
  height: 40px;
  font-size: var(--t2);
  font-weight: 500;
  line-height: 1.42;
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book__author {
  margin: 2px 0 0;
  height: 18px;
  font-size: var(--t1);
  line-height: 1.5;
  color: var(--text-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* --- Empty state --- */

.empty {
  padding: 80px var(--s4);
  text-align: center;
  color: var(--text-3);
}

.empty__icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--s4);
  border-radius: 32px;
  background: var(--surface-2);
  display: grid;
  place-items: center;
  color: var(--text-3);
}

.empty__text {
  margin: 0;
  font-size: var(--t2);
}

/* --- FAB --- */

.fab {
  position: fixed;
  right: var(--s4);
  bottom: calc(var(--nav-h) + var(--s4) + env(safe-area-inset-bottom));
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: var(--primary-container);
  color: var(--on-primary-container);
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-2);
  transition: transform var(--duration) ease;
  z-index: 20;
}

.fab:active {
  transform: scale(.94);
}

/* --- Detail --- */

.detail__head {
  display: flex;
  gap: var(--s4);
  padding: var(--s2) 0 var(--s5);
}

.detail__cover {
  flex: 0 0 116px;
  aspect-ratio: 2 / 3;
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow-1);
}

.detail__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.detail__meta {
  min-width: 0;
  padding-top: var(--s1);
}

.detail__title {
  margin: 0;
  font-size: var(--t4);
  line-height: 1.4;
  font-weight: 400;
}

.detail__sub {
  margin: var(--s2) 0 0;
  font-size: var(--t2);
  color: var(--text-2);
}

.detail__sub--fine {
  font-size: var(--t1);
  color: var(--text-3);
}

.card {
  background: var(--surface);
  border-radius: 16px;
  padding: var(--s4);
  margin-bottom: var(--s3);
}

.card__label {
  margin: 0 0 var(--s3);
  font-size: var(--t1);
  font-weight: 500;
  letter-spacing: .3px;
  color: var(--text-3);
}

.card input,
.card textarea {
  background: var(--bg);
}

.field {
  margin-bottom: var(--s4);
}

.field__label {
  display: block;
  margin-bottom: var(--s2);
  font-size: var(--t1);
  font-weight: 500;
  color: var(--text-2);
}

.field__note {
  margin: var(--s2) 0 0;
  font-size: var(--t1);
  line-height: 1.7;
  color: var(--text-3);
}

.warn {
  color: var(--danger);
}

.link {
  color: var(--primary);
  font-size: inherit;
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.saved {
  margin: var(--s2) 0 0;
  font-size: var(--t1);
  color: var(--text-3);
}

.tonal {
  display: inline-flex;
  align-items: center;
  gap: var(--s2);
  height: 40px;
  margin-top: var(--s3);
  padding: 0 var(--s4) 0 var(--s3);
  border: 1px solid var(--outline);
  border-radius: 20px;
  font-size: var(--t2);
  font-weight: 500;
  color: var(--text);
  transition: background var(--duration) ease, color var(--duration) ease, border-color var(--duration) ease;
}

.tonal:active {
  background: var(--surface-2);
}

.tonal--live {
  border-color: transparent;
  background: #FCE8E6;
  color: #C5221F;
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .tonal--live {
    background: #4A2523;
    color: #F2B8B5;
  }
}

html[data-theme="dark"] .tonal--live {
  background: #4A2523;
  color: #F2B8B5;
}

/* --- Search --- */

.search-by {
  margin-top: var(--s2);
}

.search-by + .search {
  margin-top: var(--s3);
}

.search {
  display: flex;
  align-items: center;
  gap: var(--s2);
  height: 52px;
  padding: 0 var(--s2) 0 var(--s4);
  margin-top: var(--s2);
  border-radius: 26px;
  background: var(--surface);
  transition: box-shadow var(--duration) ease, background var(--duration) ease;
}

.search:focus-within {
  background: var(--bg);
  box-shadow: var(--shadow-1);
}

.search input {
  flex: 1;
  min-width: 0;
  background: none;
  border: none;
  padding: 0;
  border-radius: 0;
}

.search input:focus {
  background: none;
}

.search__go {
  flex: 0 0 auto;
  height: 40px;
  padding: 0 var(--s4);
  border-radius: 20px;
  background: var(--primary);
  color: var(--bg);
  font-size: var(--t2);
  font-weight: 500;
  letter-spacing: .1px;
}

html[data-theme="dark"] .search__go,
:root:not([data-theme="light"]) .search__go {
  color: var(--bg);
}

.search__status {
  margin: var(--s4) 0 0;
  font-size: var(--t2);
  line-height: 1.8;
  color: var(--text-3);
}

.results {
  margin-top: var(--s3);
}

.result {
  display: flex;
  gap: var(--s4);
  width: 100%;
  padding: var(--s3) var(--s2);
  margin: 0 calc(var(--s2) * -1);
  border-radius: 12px;
  text-align: left;
  transition: background var(--duration) ease;
}

.result:active {
  background: var(--surface-2);
}

.result__cover {
  flex: 0 0 52px;
  aspect-ratio: 2 / 3;
  border-radius: 6px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: var(--shadow-1);
}

.result__cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.result__cover .book__placeholder {
  padding: var(--s2) 6px;
  font-size: 10px;
  line-height: 1.4;
}

.result__body {
  min-width: 0;
  padding-top: 2px;
}

.result__title {
  margin: 0;
  font-size: var(--t2);
  font-weight: 500;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.result__meta {
  margin: var(--s1) 0 0;
  font-size: var(--t1);
  line-height: 1.5;
  color: var(--text-2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.result__meta--fine {
  color: var(--text-3);
}

/* --- Library picker --- */

.lib {
  display: flex;
  align-items: center;
  gap: var(--s3);
  width: 100%;
  padding: var(--s3) var(--s4);
  margin-bottom: var(--s2);
  border-radius: 12px;
  background: var(--surface);
  text-align: left;
  transition: background var(--duration) ease;
}

.lib[aria-pressed="true"] {
  background: var(--primary-container);
  color: var(--on-primary-container);
}

.lib__body {
  flex: 1;
  min-width: 0;
}

.lib__name {
  margin: 0;
  font-size: var(--t2);
  font-weight: 500;
}

.lib__branches {
  margin: 2px 0 0;
  font-size: var(--t1);
  color: var(--text-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lib[aria-pressed="true"] .lib__branches {
  color: inherit;
  opacity: .75;
}

.lib__mark {
  flex: 0 0 auto;
  color: var(--outline);
}

.lib[aria-pressed="true"] .lib__mark {
  color: currentColor;
}

/* --- Availability --- */

.avail {
  padding: var(--s3) 0;
  border-top: 1px solid var(--divider);
}

.avail__head {
  display: flex;
  align-items: center;
  gap: var(--s2);
}

.avail__name {
  flex: 1;
  margin: 0;
  font-size: var(--t2);
  font-weight: 500;
}

.avail__branches {
  margin: var(--s1) 0 0;
  font-size: var(--t1);
  line-height: 1.7;
  color: var(--text-2);
}

.badge {
  flex: 0 0 auto;
  padding: 2px var(--s3);
  border-radius: 10px;
  font-size: var(--t1);
  font-weight: 500;
  background: var(--surface-2);
  color: var(--text-2);
}

.badge--ok {
  background: #E6F4EA;
  color: #137333;
}

.badge--busy {
  background: #FEF7E0;
  color: #B06000;
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .badge--ok { background: #1F3D2A; color: #81C995; }
  html:not([data-theme="light"]) .badge--busy { background: #453620; color: #FDD663; }
}

html[data-theme="dark"] .badge--ok { background: #1F3D2A; color: #81C995; }
html[data-theme="dark"] .badge--busy { background: #453620; color: #FDD663; }

/* --- Rating --- */

.rating {
  display: flex;
  gap: var(--s2);
}

.rating__star {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  color: var(--outline);
  transition: color var(--duration) ease, transform var(--duration) ease;
}

.rating__star[aria-pressed="true"] {
  color: var(--g-yellow);
}

.rating__star:active {
  transform: scale(1.15);
}

/* --- Segmented buttons --- */

.pills {
  display: flex;
}

.pill {
  flex: 1;
  height: 40px;
  border: 1px solid var(--outline);
  background: none;
  font-size: var(--t2);
  font-weight: 500;
  color: var(--text-2);
  transition: background var(--duration) ease, color var(--duration) ease;
}

.pill:first-child {
  border-radius: 20px 0 0 20px;
}

.pill:last-child {
  border-radius: 0 20px 20px 0;
  border-left: none;
}

.pill:not(:first-child):not(:last-child) {
  border-left: none;
}

.pill[aria-pressed="true"] {
  background: var(--primary-container);
  color: var(--on-primary-container);
}

/* --- Buttons --- */

.btn {
  display: block;
  width: 100%;
  height: 48px;
  border-radius: 24px;
  background: var(--primary);
  color: var(--bg);
  font-size: var(--t2);
  font-weight: 500;
  letter-spacing: .1px;
  text-align: center;
  transition: opacity var(--duration) ease;
}

.btn:active {
  opacity: .85;
}

.btn:disabled {
  background: var(--surface-2);
  color: var(--text-3);
}

.btn--quiet {
  background: none;
  color: var(--danger);
}

.btn--quiet:disabled {
  background: none;
}

/* --- Toast --- */

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(var(--nav-h) + var(--s5) + env(safe-area-inset-bottom));
  transform: translateX(-50%);
  padding: 12px var(--s4);
  border-radius: 8px;
  background: var(--text);
  color: var(--bg);
  font-size: var(--t2);
  white-space: nowrap;
  z-index: 40;
  animation: toast-in var(--duration) ease both;
  box-shadow: var(--shadow-2);
}

@keyframes toast-in {
  from { opacity: 0; transform: translate(-50%, 6px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}

/* --- Secret shelf / lock --- */

.shelf-label {
  margin: var(--s4) 0 var(--s3);
  font-size: var(--t2);
  font-weight: 500;
  color: var(--text-2);
}

.btn--neutral {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--s2);
  background: none;
  color: var(--text-2);
}

.lock {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: var(--s5);
}

.lock__icon {
  width: 64px;
  height: 64px;
  border-radius: 32px;
  background: var(--primary-container);
  color: var(--on-primary-container);
  display: grid;
  place-items: center;
}

.lock__prompt {
  margin: var(--s4) 0 0;
  font-size: var(--t3);
  color: var(--text);
  text-align: center;
}

.lock__note {
  max-width: 280px;
  text-align: center;
}

.lock__dots {
  display: flex;
  gap: var(--s4);
  margin-top: var(--s5);
}

.lock__dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid var(--outline);
  transition: background var(--duration) ease, border-color var(--duration) ease;
}

.lock__dot--on {
  background: var(--primary);
  border-color: var(--primary);
}

.lock__dots--shake {
  animation: shake 320ms ease;
}

@keyframes shake {
  0%, 100% { transform: none; }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-5px); }
  80% { transform: translateX(5px); }
}

.lock__message {
  min-height: 20px;
  margin: var(--s3) 0 0;
  font-size: var(--t1);
  color: var(--danger);
  text-align: center;
}

.lock__pad {
  display: grid;
  grid-template-columns: repeat(3, 72px);
  gap: var(--s4) var(--s5);
  margin-top: var(--s4);
}

.lock__key {
  width: 72px;
  height: 72px;
  border-radius: 36px;
  background: var(--surface-2);
  color: var(--text);
  font-size: 28px;
  font-weight: 400;
  display: grid;
  place-items: center;
  transition: background var(--duration) ease;
}

.lock__key:active {
  background: var(--primary-container);
}

.lock__forgot {
  margin-top: var(--s5);
  font-size: var(--t1);
}