:root {
  --n-ink: #17202a;
  --n-muted: #68737c;
  --n-surface: #fff;
  --n-soft: #f5f1e9;
  --n-line: #ddd5c7;
  --n-accent: #8b4b35;
  --n-accent-soft: #f0d9ce;
  --n-paper: #ead7b0;
  --n-paper-edge: #c4a875;
  --n-on-accent: #fff;
  --n-shadow: rgba(23, 32, 42, 0.1);
}

.theme-dark {
  --n-ink: #f5f1e9;
  --n-muted: #b7c0c6;
  --n-surface: #1d252c;
  --n-soft: #273139;
  --n-line: #46515a;
  --n-accent: #e39b7c;
  --n-accent-soft: #4d322c;
  --n-paper: #80694a;
  --n-paper-edge: #ae8d5e;
  --n-on-accent: #17202a;
  --n-shadow: rgba(0, 0, 0, 0.28);
}

.book-pagination-tool {
  background: var(--n-surface);
  border: 1px solid var(--n-line);
  border-radius: 1.25rem;
  box-shadow: 0 1rem 2.5rem var(--n-shadow);
  color: var(--n-ink);
  display: grid;
  gap: 1rem;
  grid-template-columns: minmax(290px, .9fr) minmax(400px, 1.1fr);
  padding: clamp(1.25rem, 3vw, 2.25rem);
}

.book-editor,
.book-output {
  min-width: 0;
}

.book-output {
  border-left: 1px solid var(--n-line);
  padding-left: clamp(1rem, 3vw, 2rem);
}

.editor-heading,
.output-heading {
  margin-bottom: 1.4rem;
}

.eyebrow {
  color: var(--n-accent);
  font-size: .7rem;
  font-weight: 900;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  letter-spacing: -.05em;
  line-height: 1;
  margin: .45rem 0;
}

p {
  color: var(--n-muted);
  line-height: 1.5;
  margin: 0;
}

label,
.field-label,
.preset-heading > span,
.unit-row > span {
  display: block;
  font-size: .78rem;
  font-weight: 800;
  margin: .85rem 0 .4rem;
}

input {
  background: var(--n-soft);
  border: 1px solid var(--n-line);
  border-radius: .6rem;
  box-sizing: border-box;
  color: var(--n-ink);
  font: inherit;
  margin-top: .35rem;
  padding: .7rem;
  width: 100%;
}

input:focus,
button:focus-visible {
  outline: 3px solid var(--n-accent-soft);
  outline-offset: 2px;
}

small {
  color: var(--n-muted);
  font-weight: 500;
}

.preset-chips,
.binding-chips,
.editor-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
}

.binding-chips {
  gap: .7rem;
  margin-top: .55rem;
}

.editor-actions {
  margin-top: .8rem;
}

button {
  background: var(--n-soft);
  border: 1px solid var(--n-line);
  border-radius: 999px;
  color: var(--n-ink);
  cursor: pointer;
  font: inherit;
  font-size: .75rem;
  font-weight: 800;
  padding: .55rem .75rem;
}

button:hover,
button.active {
  border-color: var(--n-accent);
}

.button-primary,
.unit-row button {
  background: var(--n-accent);
  border-color: var(--n-accent);
  color: var(--n-on-accent);
}

.unit-row {
  align-items: center;
  display: flex;
  justify-content: space-between;
}

.input-grid {
  display: grid;
  gap: 0 .7rem;
  grid-template-columns: 1fr 1fr;
}

.book-results {
  display: grid;
  gap: .55rem;
  grid-template-columns: repeat(2, 1fr);
}

.book-result-card {
  background: var(--n-soft);
  border-radius: .8rem;
  padding: .8rem;
}

.book-result-card span,
.book-result-card small {
  color: var(--n-muted);
  display: block;
  font-size: .64rem;
  font-weight: 800;
  text-transform: uppercase;
}

.book-result-card strong {
  display: block;
  font-size: clamp(1.2rem, 2.5vw, 1.8rem);
  margin: .3rem 0;
}

.result-pages {
  background: var(--n-accent-soft);
}

.live-badge {
  background: var(--n-accent-soft);
  border-radius: 999px;
  color: var(--n-accent);
  font-size: .62rem;
  font-weight: 900;
  letter-spacing: .1em;
  padding: .4rem .6rem;
}

.output-heading {
  align-items: flex-start;
  display: flex;
  justify-content: space-between;
}

.book-preview {
  align-items: center;
  background: var(--n-soft);
  border-radius: 1rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin-top: 1rem;
  min-height: 18rem;
  overflow: hidden;
  padding: 1rem;
  position: relative;
}

.book-shadow {
  background: var(--n-shadow);
  border-radius: 50%;
  bottom: 2.4rem;
  height: 1.5rem;
  position: absolute;
  width: 15rem;
}

.book-mockup {
  align-items: stretch;
  display: flex;
  height: 12rem;
  perspective: 45rem;
  transform: rotate(-5deg);
  z-index: 1;
}

.book-cover {
  align-items: center;
  background: var(--n-paper);
  border: 1px solid var(--n-paper-edge);
  color: var(--n-ink);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1rem;
  width: 7.5rem;
}

.book-cover.front {
  box-shadow: .6rem .6rem .8rem var(--n-shadow);
  transform: rotateY(-8deg);
}

.book-cover.back {
  transform: rotateY(8deg);
}

.book-cover span {
  font-size: .55rem;
  font-weight: 900;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.book-cover strong {
  font-size: 1.4rem;
  text-align: center;
}

.book-spine {
  background: var(--n-accent);
  width: var(--book-spine);
}

.book-preview p,
.source-note {
  font-size: .72rem;
  margin-top: 1rem;
  text-align: center;
}

@media (max-width: 760px) {
  .book-pagination-tool {
    grid-template-columns: 1fr;
  }

  .book-output {
    border-left: 0;
    border-top: 1px solid var(--n-line);
    padding-left: 0;
    padding-top: 1.5rem;
  }
}