:root {
  --font-display: "Fraunces", "Palatino Linotype", Palatino, serif;
  --font-body: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Palatino, serif;
  --font-ui: "Source Sans 3", "Segoe UI", sans-serif;
  --paper: #f3ead6;
  --ink: #2a241c;
  --ink-soft: #5a5248;
  --chrome: #1c2a1e;
  --chrome-2: #243428;
  --leaf: #5c7a4a;
  --ivy: #3d5a40;
  --rose: #a85a4a;
  --gold: #b08a3e;
  --rule: rgba(42, 36, 28, 0.12);
  --shadow: 0 24px 60px rgba(16, 20, 14, 0.22);
  --page-width: 38rem;
  --font-size: 1.25rem;
  color-scheme: light;
}

[data-theme="parchment"] {
  --paper: #e8d5b5;
  --ink: #3a2a18;
  --ink-soft: #6a5338;
  --chrome: #3d2a1c;
  --chrome-2: #4a3424;
  --leaf: #8a6a32;
  --ivy: #6a4e28;
  --rose: #9a4a38;
  --gold: #c4a056;
  --rule: rgba(58, 42, 24, 0.14);
}

[data-theme="night"] {
  --paper: #161410;
  --ink: #e8dcc4;
  --ink-soft: #b8ad96;
  --chrome: #0c0b09;
  --chrome-2: #1a1814;
  --leaf: #9cba78;
  --ivy: #7a9460;
  --rose: #d48878;
  --gold: #d4b46a;
  --rule: rgba(232, 220, 196, 0.12);
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body.is-reading,
body.is-practice {
  height: 100dvh;
  overflow: hidden;
}

body {
  font-family: var(--font-ui);
  background: var(--chrome);
  color: var(--ink);
}

button, input {
  font: inherit;
}

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Cover */

.cover {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 2.5rem 1.25rem;
  background:
    radial-gradient(ellipse at 50% 20%, rgba(176, 138, 62, 0.12), transparent 46%),
    linear-gradient(180deg, var(--chrome-2), var(--chrome));
  color: #f3ead6;
}

.cover-plate {
  width: min(42rem, 100%);
  border: 1px solid rgba(243, 234, 214, 0.18);
  background: rgba(12, 16, 12, 0.35);
  box-shadow: var(--shadow);
  padding: 2.4rem 1.6rem 2rem;
  text-align: center;
}

.cover-art {
  width: min(16rem, 70vw);
  height: auto;
  margin: 0 auto 1.4rem;
  display: block;
}

.cover-kicker {
  letter-spacing: 0.32em;
  text-transform: uppercase;
  font-size: 0.72rem;
  color: var(--gold);
  margin: 0 0 0.7rem;
}

.cover h1 {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(2.4rem, 8vw, 4.4rem);
  line-height: 0.95;
  margin: 0 0 0.7rem;
  font-style: italic;
}

.cover-author {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: rgba(243, 234, 214, 0.78);
}

.cover-meta {
  margin: 1.1rem 0 0;
  color: rgba(243, 234, 214, 0.55);
  font-size: 0.88rem;
}

.cover-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  justify-content: center;
  margin-top: 1.8rem;
}

.btn {
  min-height: 2.7rem;
  padding: 0 1.1rem;
  border: 1px solid rgba(243, 234, 214, 0.28);
  color: #f3ead6;
  letter-spacing: 0.04em;
}

.btn:hover { border-color: var(--gold); color: var(--gold); }

.btn-solid {
  background: #f3ead6;
  color: #1c2a1e;
  border-color: #f3ead6;
}

.btn-solid:hover { background: #fff6e4; color: #1c2a1e; }

/* Chrome */

.reader {
  height: 100dvh;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
}

.topbar,
.bottombar {
  position: relative;
  z-index: 4;
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.55rem 0.75rem;
  background: color-mix(in srgb, var(--chrome) 92%, transparent);
  color: #f3ead6;
}

.topbar { border-bottom: 1px solid rgba(243, 234, 214, 0.08); }
.bottombar { border-top: 1px solid rgba(243, 234, 214, 0.08); justify-content: space-between; }

.icon-btn {
  width: 2.4rem;
  height: 2.4rem;
  display: grid;
  place-items: center;
  border-radius: 999px;
  color: #f3ead6;
}

.icon-btn:hover,
.icon-btn[aria-expanded="true"] {
  background: rgba(243, 234, 214, 0.08);
  color: var(--gold);
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

.brand {
  flex: 1;
  min-width: 0;
  text-align: center;
}

.brand-title {
  display: block;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.05rem;
  line-height: 1.1;
}

.brand-chapter {
  display: block;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(243, 234, 214, 0.62);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: rgba(243, 234, 214, 0.08);
}

.progress > span {
  display: block;
  height: 100%;
  width: 0;
  background: var(--gold);
}

/* Book stage */

.stage {
  position: relative;
  min-height: 0;
  display: grid;
  place-items: center;
  padding: 0.7rem 2.6rem 0.9rem;
}

.hot-zone {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 12%;
  z-index: 3;
}

.hot-left { left: 0; }
.hot-right { right: 0; }
.stage.on-practice .hot-zone { pointer-events: none; }

.book {
  position: relative;
  width: min(var(--page-width), 100%);
  height: 100%;
  perspective: 1600px;
  transform-style: preserve-3d;
}

.book.is-turning {
  overflow: visible;
}

.leaf {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(42, 36, 28, 0.06), transparent 18px),
    var(--paper);
  color: var(--ink);
  box-shadow: var(--shadow);
  transform-origin: left center;
  overflow: hidden;
  backface-visibility: hidden;
}

.leaf.is-now { z-index: 2; }
.leaf.is-under { z-index: 1; }
.leaf.to-left,
.leaf.to-right {
  z-index: 3;
  pointer-events: none;
}

.leaf.to-left {
  transform-origin: left center;
  animation: leaf-away-left 0.52s cubic-bezier(0.4, 0.0, 0.2, 1) forwards;
}

.leaf.to-right {
  transform-origin: right center;
  animation: leaf-away-right 0.52s cubic-bezier(0.4, 0.0, 0.2, 1) forwards;
}

.leaf.to-left::after,
.leaf.to-right::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.22), transparent 46%);
}

@keyframes leaf-away-left {
  to { transform: rotateY(-90deg); }
}

@keyframes leaf-away-right {
  to { transform: rotateY(90deg); }
}

.leaf-inner {
  height: 100%;
  padding: clamp(1.2rem, 3.4vw, 2.4rem) clamp(1.2rem, 4vw, 2.8rem) 2.9rem;
  overflow: hidden;
}

.leaf-inner.is-practice {
  overflow: auto;
  font-family: var(--font-ui);
  font-size: 0.95rem;
}

.reader.is-practice-view {
  height: 100dvh;
}

.leaf-num {
  position: absolute;
  right: 1.1rem;
  bottom: 0.7rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--ink-soft);
}

.probe {
  position: absolute;
  left: -140vw;
  top: 0;
  overflow: hidden;
  visibility: hidden;
  pointer-events: none;
}

.leaf-inner.is-title {
  display: grid;
  place-items: center;
  text-align: center;
}

.leaf-head {
  width: min(28rem, 100%);
}

.leaf-head h1 {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(2rem, 4.4vw, 3rem);
  line-height: 1.15;
  margin: 0 0 0.8rem;
}

.leaf-inner.is-title .chapter-num {
  margin-bottom: 0.8rem;
}

.leaf-inner.is-title .chapter-time {
  margin: 0 0 1.4rem;
}

.leaf-inner.is-title .ornament {
  margin-bottom: 0;
}

/* Page */

.page {
  width: min(var(--page-width), calc(100% - 2rem));
  margin: 1.6rem auto 5rem;
  background: var(--paper);
  color: var(--ink);
  box-shadow: var(--shadow);
  padding: clamp(1.6rem, 4vw, 3.2rem) clamp(1.3rem, 5vw, 3.6rem) 3.4rem;
}

.chapter-num {
  font-family: var(--font-display);
  letter-spacing: 0.28em;
  text-transform: uppercase;
  font-size: 0.74rem;
  color: var(--rose);
  margin: 0 0 0.45rem;
}

.page h1 {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  line-height: 1.15;
  margin: 0 0 0.35rem;
}

.chapter-time {
  margin: 0 0 1.6rem;
  color: var(--ink-soft);
  font-size: 0.88rem;
}

.ornament {
  display: block;
  width: 7rem;
  height: 14px;
  margin: 0 auto 1.8rem;
}

.chapter-body {
  font-family: var(--font-body);
  font-size: var(--font-size);
  line-height: 1.7;
  overflow-wrap: break-word;
}

.chapter-body p {
  margin: 0 0 1.05em;
}

.chapter-body.is-first > p:first-of-type::first-letter {
  font-family: var(--font-display);
  float: left;
  font-size: 3.5em;
  line-height: 0.78;
  padding: 0.08em 0.1em 0 0;
  color: var(--ivy);
}

.chapter-body blockquote {
  margin: 1.4em 0;
  padding: 1rem 1.1rem;
  border-left: 2px solid var(--gold);
  background: color-mix(in srgb, var(--gold) 8%, transparent);
  font-style: italic;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  flex-shrink: 0;
  white-space: nowrap;
  line-height: 1;
  color: #f3ead6;
  min-height: 2.4rem;
  padding: 0 0.4rem;
}

.nav-btn svg {
  display: block;
  width: 1.1rem;
  height: 1.1rem;
}

.nav-btn:disabled {
  opacity: 0.35;
  cursor: default;
}

.bottom-center {
  color: rgba(243, 234, 214, 0.62);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: center;
}

.practice-stage {
  min-height: 0;
  overflow: auto;
  padding: 0.8rem 1rem 1.4rem;
}

.practice-sheet {
  width: min(var(--page-width), 100%);
  margin: 0 auto;
  background: var(--paper);
  color: var(--ink);
  box-shadow: var(--shadow);
  padding: clamp(1.3rem, 3.5vw, 2.4rem) clamp(1.2rem, 4vw, 2.6rem) 2.2rem;
}

/* Panels */

.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(8, 10, 8, 0.46);
  z-index: 8;
}

.panel {
  position: fixed;
  top: 0;
  bottom: 0;
  width: min(22rem, 92vw);
  background: var(--chrome-2);
  color: #f3ead6;
  z-index: 9;
  overflow: auto;
  padding: 1.1rem 1rem 2rem;
  box-shadow: var(--shadow);
}

.panel-left { left: 0; }
.panel-right { right: 0; }

.panel h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 560;
  margin: 0.2rem 0 1rem;
}

.toc-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.35rem;
  margin: 0 0 0.9rem;
}

.toc-tab {
  min-height: 2.2rem;
  border: 1px solid rgba(243, 234, 214, 0.22);
  letter-spacing: 0.06em;
}

.toc-tab[aria-selected="true"] {
  background: #f3ead6;
  color: #1c2a1e;
  border-color: #f3ead6;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.toc-list button {
  width: 100%;
  text-align: left;
  padding: 0.7rem 0.55rem;
  border-bottom: 1px solid rgba(243, 234, 214, 0.08);
  display: grid;
  grid-template-columns: 2.2rem 1fr;
  gap: 0.4rem;
}

.toc-list button:hover,
.toc-list button[aria-current="page"] {
  background: rgba(243, 234, 214, 0.06);
}

.toc-list button[aria-current="page"] {
  color: var(--gold);
}

.toc-roman {
  color: var(--gold);
  font-size: 0.78rem;
  padding-top: 0.18rem;
}

.field {
  display: grid;
  gap: 0.35rem;
  margin-bottom: 1.1rem;
}

.field span {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(243, 234, 214, 0.62);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.chip {
  border: 1px solid rgba(243, 234, 214, 0.22);
  min-height: 2.1rem;
  padding: 0 0.75rem;
}

.chip[aria-pressed="true"] {
  background: #f3ead6;
  color: #1c2a1e;
  border-color: #f3ead6;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--gold);
}

.search {
  width: 100%;
  margin-bottom: 0.9rem;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(243, 234, 214, 0.16);
  color: #f3ead6;
  padding: 0.65rem 0.7rem;
}

.search::placeholder { color: rgba(243, 234, 214, 0.45); }

.help {
  margin-top: 1.4rem;
  color: rgba(243, 234, 214, 0.55);
  font-size: 0.85rem;
  line-height: 1.55;
}

.help kbd {
  display: inline-block;
  border: 1px solid rgba(243, 234, 214, 0.22);
  padding: 0 0.3rem;
  font-size: 0.78rem;
}

.to-practice {
  margin: 2.2rem 0 0;
  text-align: center;
}

.to-practice button {
  color: var(--ivy);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.82rem;
  border-bottom: 1px solid var(--gold);
  padding: 0.2rem 0;
}

.workbook {
  margin: 0;
  padding: 0 0 1.5rem;
  font-family: var(--font-ui);
  font-size: 0.95rem;
}

.workbook h2 {
  font-family: var(--font-display);
  font-size: 1.7rem;
  font-weight: 560;
  margin: 0 0 0.35rem;
}

.workbook h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 560;
  margin: 1.6rem 0 0.7rem;
}

.workbook-lead,
.bank-label {
  color: var(--ink-soft);
  margin: 0 0 1rem;
}

.vocab {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.vocab th,
.vocab td {
  border-bottom: 1px solid var(--rule);
  text-align: left;
  padding: 0.55rem 0.4rem;
  vertical-align: top;
}

.vocab thead th {
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.72rem;
  color: var(--ink-soft);
  font-weight: 600;
}

.vocab tbody th {
  font-family: var(--font-body);
  font-weight: 600;
  color: var(--ivy);
  padding-right: 1rem;
}

.q {
  border: 1px solid var(--rule);
  margin: 0 0 0.7rem;
  padding: 0.7rem 0.8rem 0.85rem;
}

.q legend {
  padding: 0 0.35rem;
  font-weight: 600;
}

.choice {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  padding: 0.28rem 0;
  cursor: pointer;
}

.q.is-right { border-color: var(--leaf); }
.q.is-wrong { border-color: var(--rose); }
.gap.is-right input { border-color: var(--leaf); }
.gap.is-wrong input { border-color: var(--rose); }

.bank {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0 0 1rem;
}

.bank-word {
  border: 1px solid var(--rule);
  padding: 0.2rem 0.55rem;
  color: var(--ivy);
  font-family: var(--font-body);
}

.gap {
  display: block;
  margin: 0 0 0.85rem;
  line-height: 1.6;
}

.gap input {
  width: 9.5rem;
  margin: 0 0.15rem;
  padding: 0.2rem 0.4rem;
  border: 0;
  border-bottom: 1px solid var(--gold);
  background: transparent;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1em;
}

.work-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1.2rem;
}

.btn-check,
.btn-reset {
  min-height: 2.4rem;
  padding: 0 0.95rem;
  border: 1px solid var(--ivy);
}

.btn-check {
  background: var(--ivy);
  color: #f3ead6;
}

.btn-reset { color: var(--ivy); }

.work-score {
  margin: 1rem 0 0;
  font-family: var(--font-display);
  font-size: 1.2rem;
}

@media (max-width: 700px) {
  .cover {
    padding: 1.4rem 1rem;
    padding-top: max(1.4rem, env(safe-area-inset-top));
    padding-bottom: max(1.4rem, env(safe-area-inset-bottom));
  }

  .cover-plate { padding: 1.6rem 1.1rem 1.4rem; }

  .topbar,
  .bottombar {
    gap: 0.15rem;
    padding: 0.35rem 0.4rem;
  }

  .topbar {
    padding-top: max(0.35rem, env(safe-area-inset-top));
  }

  .bottombar {
    padding-bottom: max(0.35rem, env(safe-area-inset-bottom));
  }

  .icon-btn {
    width: 2.15rem;
    height: 2.15rem;
  }

  .brand-title { display: none; }

  .brand-chapter {
    font-size: 0.8rem;
    letter-spacing: 0.02em;
    text-transform: none;
  }

  .stage {
    padding: 0.55rem 0.7rem 0.65rem;
  }

  .hot-zone { width: 12%; }

  .leaf-inner {
    padding: 1.2rem 1.15rem 2.85rem;
  }

  .leaf-inner.is-practice {
    padding: 1.15rem 1.05rem 1.5rem;
  }

  .leaf-inner.is-title {
    padding-bottom: 2.4rem;
  }

  .leaf-num {
    right: 0.95rem;
    bottom: 0.55rem;
  }

  .leaf-head h1 {
    font-size: clamp(1.7rem, 8vw, 2.35rem);
  }

  .chapter-body {
    font-size: calc(var(--font-size) * 0.9);
    line-height: 1.65;
  }

  .chapter-body.is-first > p:first-of-type::first-letter {
    font-size: 2.55em;
    line-height: 0.86;
  }

  .nav-label { display: none; }

  .nav-btn { padding: 0 0.35rem; }

  .bottom-center {
    letter-spacing: 0.04em;
    font-size: 0.75rem;
  }

  .field-measure,
  .help { display: none; }

  .panel {
    width: 100%;
    padding-top: max(1.1rem, env(safe-area-inset-top));
    padding-bottom: max(2rem, env(safe-area-inset-bottom));
  }

  .vocab thead { display: none; }

  .vocab,
  .vocab tbody,
  .vocab tr,
  .vocab th,
  .vocab td {
    display: block;
    width: 100%;
  }

  .vocab tr {
    padding: 0.7rem 0;
  }

  .vocab th {
    border-bottom: 0;
    padding: 0 0 0.15rem;
  }

  .vocab td {
    border-bottom: 1px solid var(--rule);
    padding: 0 0 0.7rem;
    color: var(--ink-soft);
  }

  .choice {
    min-height: 2.35rem;
    padding: 0.4rem 0;
  }

  .gap input {
    width: min(100%, 12rem);
    display: inline-block;
  }
}

@media (prefers-reduced-motion: reduce) {
  .leaf.to-left,
  .leaf.to-right { animation: none; }
}

@media print {
  .topbar, .bottombar, .backdrop, .panel { display: none !important; }
  body { background: white; }
  .page { box-shadow: none; width: 100%; margin: 0; }
}