/* ==========================================================================
   Hướng Đến Nhập Lưu — reading site
   Editorial reading system built on the book's own saffron/forest palette.
   One shared radius scale, one accent family, both light and dark modes.
   ========================================================================== */

:root {
  color-scheme: light dark;

  --font-serif: "Literata", "Iowan Old Style", "Palatino Linotype", "Book Antiqua",
    Georgia, "Times New Roman", serif;
  --font-sans: "Be Vietnam Pro", "Inter", -apple-system, BlinkMacSystemFont,
    "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --paper: #fbf9f4;
  --paper-2: #f4efe6;
  --surface: #ffffff;
  --surface-2: #f8f4ec;
  --surface-3: #f1ebe0;

  --ink: #211d18;
  --ink-soft: #4a423a;
  --muted: #6f665b;
  --faint: #928878;

  --rule: #e4ddcf;
  --rule-strong: #cec4b2;

  --saffron: #a75d20;
  --saffron-soft: #c17c41;
  --saffron-tint: #f6ecdf;
  --forest: #2f5a49;
  --forest-tint: #e8f0eb;
  --clay: #8b4f3d;
  --clay-tint: #f7ece7;
  --indigo: #4d5372;
  --indigo-tint: #eceef4;
  --research: #3d6687;
  --research-tint: #e9f0f5;

  --accent: var(--saffron);
  --focus: #1c6ea4;

  --sidebar-w: 19rem;
  --toc-w: 15rem;
  --content-w: 45rem;

  --radius-sm: 6px;
  --radius: 12px;
  --radius-lg: 18px;

  --shadow-sm: 0 1px 2px rgba(60, 44, 24, 0.06), 0 2px 8px rgba(60, 44, 24, 0.05);
  --shadow-md: 0 10px 30px -12px rgba(60, 44, 24, 0.28), 0 2px 6px rgba(60, 44, 24, 0.06);

  --topbar-h: 3.6rem;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='2'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='0.5'/%3E%3C/svg%3E");
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #16130f;
  --paper-2: #1c1814;
  --surface: #201c16;
  --surface-2: #262119;
  --surface-3: #2c261d;
  --ink: #efe8dc;
  --ink-soft: #d7cfc1;
  --muted: #a79d8e;
  --faint: #807767;
  --rule: #332c22;
  --rule-strong: #4c4132;
  --saffron: #e2a468;
  --saffron-soft: #cf8b4d;
  --saffron-tint: #2c2117;
  --forest: #8cc4ac;
  --forest-tint: #1a2620;
  --clay: #dda08d;
  --clay-tint: #2b1d18;
  --indigo: #b8bedb;
  --indigo-tint: #1d1f2b;
  --research: #92bce0;
  --research-tint: #16232d;
  --focus: #7cc0f0;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 14px 36px -14px rgba(0, 0, 0, 0.7);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --paper: #16130f;
    --paper-2: #1c1814;
    --surface: #201c16;
    --surface-2: #262119;
    --surface-3: #2c261d;
    --ink: #efe8dc;
    --ink-soft: #d7cfc1;
    --muted: #a79d8e;
    --faint: #807767;
    --rule: #332c22;
    --rule-strong: #4c4132;
    --saffron: #e2a468;
    --saffron-soft: #cf8b4d;
    --saffron-tint: #2c2117;
    --forest: #8cc4ac;
    --forest-tint: #1a2620;
    --clay: #dda08d;
    --clay-tint: #2b1d18;
    --indigo: #b8bedb;
    --indigo-tint: #1d1f2b;
    --research: #92bce0;
    --research-tint: #16232d;
    --focus: #7cc0f0;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 14px 36px -14px rgba(0, 0, 0, 0.7);
  }
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--topbar-h) + 1rem);
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 0.45vw + 0.98rem, 1.19rem);
  line-height: 1.78;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    radial-gradient(60rem 40rem at 110% -10%, var(--saffron-tint), transparent 60%),
    radial-gradient(50rem 36rem at -10% 0%, var(--forest-tint), transparent 55%);
  background-attachment: fixed;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 60;
  pointer-events: none;
  opacity: 0.035;
  background-image: var(--grain);
  mix-blend-mode: multiply;
}

:root[data-theme="dark"] body::before {
  opacity: 0.05;
  mix-blend-mode: screen;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) body::before {
    opacity: 0.05;
    mix-blend-mode: screen;
  }
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--accent);
  text-decoration-color: color-mix(in oklab, var(--accent) 40%, transparent);
  text-underline-offset: 0.16em;
}

a:hover {
  color: color-mix(in oklab, var(--accent) 80%, var(--ink));
}

:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
  border-radius: 3px;
}

::selection {
  background: color-mix(in oklab, var(--saffron) 25%, transparent);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--surface);
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  box-shadow: var(--shadow-md);
}

.skip-link:focus {
  top: 0.75rem;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.35rem;
  height: 2.35rem;
  padding: 0;
  color: var(--ink-soft);
  background: transparent;
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.icon-btn:hover {
  color: var(--ink);
  background: var(--surface-2);
  border-color: var(--rule);
}

.icon-btn:active {
  transform: translateY(1px);
}

/* --------------------------------------------------------------------------
   Progress + layout
   -------------------------------------------------------------------------- */

.reading-progress {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 70;
  height: 3px;
  background: transparent;
}

.reading-progress span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--forest), var(--saffron));
  transform-origin: left center;
  transition: width 0.12s linear;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  max-width: 100rem;
  margin: 0 auto;
}

.page {
  min-width: 0;
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

.content {
  width: 100%;
  max-width: var(--content-w);
  margin-inline: auto;
  padding: clamp(1.6rem, 4vw, 3rem) clamp(1.1rem, 4vw, 2rem) 3rem;
  flex: 1;
}

/* --------------------------------------------------------------------------
   Topbar
   -------------------------------------------------------------------------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  height: var(--topbar-h);
  padding: 0 clamp(0.7rem, 3vw, 1.4rem);
  background: color-mix(in oklab, var(--paper) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--rule);
}

.topbar-menu {
  display: inline-flex;
}

.topbar-home {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--ink-soft);
  text-decoration: none;
  white-space: nowrap;
}

.topbar-home svg {
  opacity: 0.6;
}

.topbar-home:hover {
  color: var(--accent);
}

.topbar-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--muted);
  text-align: center;
}

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

/* --------------------------------------------------------------------------
   Sidebar
   -------------------------------------------------------------------------- */

.sidebar {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  height: 100dvh;
  padding: 0.9rem 0.75rem 0.75rem;
  background: color-mix(in oklab, var(--paper-2) 70%, var(--paper));
  border-right: 1px solid var(--rule);
}

.sidebar-head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.35rem 0.85rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-width: 0;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 30%, var(--saffron), var(--saffron-soft));
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.35);
}

.brand-mark span {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--paper);
  box-shadow: 0 0 0 2px color-mix(in oklab, var(--paper) 60%, transparent);
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.2;
}

.brand-text strong {
  font-family: var(--font-serif);
  font-size: 0.98rem;
  font-weight: 600;
}

.brand-text small {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sidebar-close {
  display: none;
  margin-left: auto;
}

.sidebar-body {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  scrollbar-width: thin;
  padding-right: 0.15rem;
}

.sidebar-foot {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  padding: 0.7rem 0.35rem 0.2rem;
  border-top: 1px solid var(--rule);
}

.side-download {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.3rem 0.6rem;
  font-family: var(--font-sans);
  font-size: 0.74rem;
  font-weight: 600;
  color: var(--ink-soft);
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 999px;
  text-decoration: none;
}

.side-download:hover {
  border-color: var(--saffron-soft);
  color: var(--accent);
}

.side-download-quiet {
  color: var(--muted);
  background: transparent;
}

/* TOC list */

.toc {
  font-family: var(--font-sans);
}

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

.toc-sublist .toc-sublist {
  margin: 0.1rem 0 0.3rem 0.55rem;
  padding-left: 0.6rem;
  border-left: 1px solid var(--rule);
}

.toc-item,
.toc-group {
  margin: 0;
}

.toc-group > details > summary {
  display: flex;
  align-items: center;
  gap: 0.2rem;
  list-style: none;
  cursor: pointer;
}

.toc-group > details > summary::-webkit-details-marker {
  display: none;
}

.toc-chevron {
  flex: none;
  width: 0.55rem;
  height: 0.55rem;
  margin-left: auto;
  border-right: 1.5px solid var(--faint);
  border-bottom: 1.5px solid var(--faint);
  transform: rotate(-45deg);
  transition: transform 0.2s var(--ease);
}

.toc-group details[open] > summary .toc-chevron {
  transform: rotate(45deg);
}

.toc-link {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex: 1;
  min-width: 0;
  padding: 0.34rem 0.5rem;
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  font-size: 0.84rem;
  line-height: 1.35;
  text-decoration: none;
  transition: background 0.15s var(--ease), color 0.15s var(--ease);
}

.toc-link:hover {
  background: var(--surface);
  color: var(--ink);
}

.toc-group-link {
  font-weight: 600;
  color: var(--ink);
}

.toc-group-label {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.34rem 0.5rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
}

.toc-num {
  flex: none;
  display: inline-grid;
  place-items: center;
  min-width: 1.4rem;
  height: 1.4rem;
  padding: 0 0.28rem;
  border-radius: 999px;
  background: var(--surface-3);
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.toc-link.is-active {
  background: var(--saffron-tint);
  color: var(--accent);
  font-weight: 600;
  box-shadow: inset 2px 0 0 var(--saffron);
}

.toc-link.is-active .toc-num {
  background: var(--saffron);
  color: #fff;
}

/* --------------------------------------------------------------------------
   Page table of contents
   -------------------------------------------------------------------------- */

.page-toc {
  display: none;
  align-self: start;
  position: sticky;
  top: var(--topbar-h);
  max-height: calc(100dvh - var(--topbar-h));
  overflow-y: auto;
  padding: 2rem 1.5rem 2rem 0.5rem;
  font-family: var(--font-sans);
}

.ptoc-title {
  margin: 0 0 0.6rem;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--faint);
}

.ptoc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--rule);
}

.ptoc-item a {
  display: block;
  padding: 0.3rem 0.2rem 0.3rem 0.8rem;
  margin-left: -1px;
  border-left: 2px solid transparent;
  font-size: 0.79rem;
  line-height: 1.4;
  color: var(--muted);
  text-decoration: none;
}

.ptoc-item a:hover {
  color: var(--ink);
}

.ptoc-item a.is-active {
  border-left-color: var(--saffron);
  color: var(--accent);
  font-weight: 600;
}

.ptoc-l3 a,
.ptoc-l4 a {
  padding-left: 1.4rem;
  font-size: 0.75rem;
}

/* --------------------------------------------------------------------------
   Prose
   -------------------------------------------------------------------------- */

.prose {
  max-width: 100%;
}

.prose > p,
.prose > ul,
.prose > ol,
.prose > blockquote {
  max-width: 68ch;
}

.prose h1,
.prose h2,
.prose h3,
.prose h4,
.prose h5 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.22;
  color: var(--ink);
  scroll-margin-top: calc(var(--topbar-h) + 1rem);
}

.prose h1 {
  font-size: clamp(1.85rem, 3.4vw, 2.5rem);
  letter-spacing: -0.015em;
  margin: 0 0 0.8rem;
}

.prose h2 {
  font-size: clamp(1.35rem, 1.7vw, 1.62rem);
  margin: 3rem 0 0.9rem;
  padding-top: 0.2rem;
}

.prose > h2::before {
  content: "";
  display: block;
  width: 2.1rem;
  height: 2px;
  margin-bottom: 0.85rem;
  background: var(--saffron);
  opacity: 0.7;
}

.prose h3 {
  font-size: 1.16rem;
  margin: 2.1rem 0 0.6rem;
  color: color-mix(in oklab, var(--ink) 88%, var(--saffron));
}

.prose h4 {
  font-size: 1rem;
  margin: 1.6rem 0 0.5rem;
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--ink-soft);
}

.prose h5 {
  font-size: 0.92rem;
  margin: 1.3rem 0 0.4rem;
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--muted);
}

.prose p {
  margin: 0 0 1.05rem;
}

.prose strong {
  font-weight: 600;
}

.prose em {
  font-style: italic;
}

.prose ul,
.prose ol {
  margin: 0 0 1.15rem;
  padding-left: 1.35rem;
}

.prose li {
  margin: 0.4rem 0;
  padding-left: 0.2rem;
}

.prose li::marker {
  color: var(--saffron-soft);
}

.prose blockquote {
  margin: 1.6rem 0;
  padding: 0.4rem 0 0.4rem 1.2rem;
  border-left: 3px solid var(--forest);
  font-style: italic;
  color: var(--ink-soft);
}

.prose hr {
  border: 0;
  height: 1px;
  margin: 2.4rem auto;
  width: 60%;
  background: var(--rule-strong);
}

.prose table {
  width: 100%;
  margin: 1.6rem 0;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.prose th,
.prose td {
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--rule);
  text-align: left;
  vertical-align: top;
}

.prose thead th {
  background: var(--surface-2);
  font-family: var(--font-sans);
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.prose tbody tr:nth-child(even) {
  background: color-mix(in oklab, var(--surface-2) 55%, transparent);
}

.prose cite {
  font-style: normal;
}

/* Chapter / part / introduction openers */

.introduction-opener,
.chapter-opener,
.part-opener {
  position: relative;
  margin-bottom: 1.6rem;
}

.chapter-opener {
  margin-top: 0.5rem;
  padding-top: 1.6rem;
  border-top: 2px solid var(--saffron);
}

.part-opener {
  margin-top: 0.5rem;
  padding-top: 2rem;
  border-top: 3px solid var(--forest);
}

.introduction-opener {
  text-align: left;
}

.page-intro .prose > p:first-of-type::first-letter {
  float: left;
  font-size: 3.4em;
  line-height: 0.82;
  padding: 0.08em 0.12em 0 0;
  font-weight: 600;
  color: var(--saffron);
}

.eyebrow,
.chapter-number,
.cover-kicker,
.cover-edition,
.day-duration,
.quote-source {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
}

.eyebrow {
  margin: 0 0 0.5rem;
}

.prose .kicker {
  color: var(--saffron);
}

.chapter-number {
  color: var(--saffron);
  margin: 0 0 0.4rem;
}

.chapter-deck,
.part-deck {
  font-family: var(--font-sans) !important;
  font-size: 0.98rem;
  line-height: 1.6;
  color: var(--muted);
  max-width: 40rem;
  margin: 0.6rem 0 0 !important;
}

.provenance {
  margin: 1rem 0 0;
}

/* Source colour system */

.source-badge {
  display: inline-block;
  padding: 0.16rem 0.5rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  white-space: nowrap;
}

.source-badge.source-kinh { color: var(--forest); }
.source-badge.source-luan-giai { color: var(--indigo); }
.source-badge.source-thanh-tinh-dao { color: var(--saffron); }
.source-badge.source-mahasi,
.source-badge.source-caution { color: var(--clay); }
.source-badge.source-nghien-cuu { color: var(--research); }
.source-badge.source-bien-soan { color: var(--muted); }

.source-line .source-badge,
.modern-note .source-badge {
  display: block;
  width: fit-content;
  margin: 0 0 0.55rem;
}

.source-line,
.modern-note {
  margin: 1.3rem 0;
  padding: 0.15rem 0 0.15rem 1rem;
  border-left: 3px solid var(--forest);
  color: var(--ink-soft);
  font-size: 0.97rem;
}

.source-line p:last-child,
.modern-note p:last-child {
  margin-bottom: 0;
}

.modern-note {
  border-left-color: var(--rule-strong);
  color: var(--muted);
}

.source-line strong,
.modern-note strong {
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* Cards */

.practice-card,
.caution,
.scripture-quote,
.reference-item {
  position: relative;
  margin: 1.5rem 0;
  padding: 1.1rem 1.2rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.practice-card {
  background: var(--surface-2);
  border-left: 3px solid var(--saffron);
}

.practice-card .card-title {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--saffron);
}

.caution {
  background: var(--clay-tint);
  border-left: 3px solid var(--clay);
}

.caution .card-title {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--clay);
}

.scripture-quote {
  background: var(--forest-tint);
  border-left: 3px solid var(--forest);
  font-style: italic;
}

.card-title {
  margin: 0 0 0.5rem;
  font-size: 1.02rem;
  font-weight: 600;
  overflow-wrap: anywhere;
}

.caution .card-title {
  margin-top: 0.6rem;
}

.quote-source {
  margin: 0.8rem 0 0 !important;
  text-transform: none;
  letter-spacing: 0.02em;
  font-weight: 600;
}

/* FAQ cards */

.faq-card {
  scroll-margin-top: calc(var(--topbar-h) + 1rem);
}

.faq-card .card-title {
  font-family: var(--font-serif);
  font-size: 1.14rem;
  letter-spacing: 0;
  text-transform: none;
  color: var(--ink);
}

/* Decision / concept maps and flow ribbons */

.decision-map,
.concept-map {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin: 1.6rem 0;
}

.concept-map-three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.decision-node,
.concept-node {
  min-width: 0;
  padding: 1rem 1.05rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--saffron);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.decision-node:nth-child(1) { border-top-color: var(--clay); }
.decision-node:nth-child(2) { border-top-color: var(--forest); }
.decision-node:nth-child(3) { border-top-color: var(--indigo); }
.decision-node:nth-child(4) { border-top-color: var(--saffron); }
.decision-wide { grid-column: 1 / -1; }

.concept-node:nth-child(4n + 1) { border-top-color: var(--clay); }
.concept-node:nth-child(4n + 2) { border-top-color: var(--saffron); }
.concept-node:nth-child(4n + 3) { border-top-color: var(--forest); }
.concept-node:nth-child(4n) { border-top-color: var(--indigo); }

.concept-node .eyebrow {
  margin: 0 0 0.3rem;
}

.concept-node .card-title {
  margin-top: 0;
}

.flow-ribbon {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  margin: 1.5rem 0;
  padding: 0.8rem;
  list-style: none;
  background: var(--surface-2);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.flow-ribbon li {
  display: inline-flex;
  align-items: center;
  margin: 0;
  padding: 0.3rem 0.55rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
}

.flow-ribbon li:not(:last-child)::after {
  content: "\2192";
  margin-left: 0.5rem;
  color: var(--saffron);
}

/* Day cards, worksheet, check rows */

.day-card {
  margin: 1.1rem 0;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--rule);
}

.day-number {
  display: inline-grid;
  place-items: center;
  min-width: 1.7rem;
  height: 1.7rem;
  margin-right: 0.5rem;
  padding: 0 0.3rem;
  border-radius: 999px;
  background: var(--saffron);
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.76rem;
  font-weight: 700;
}

.day-title {
  font-weight: 600;
}

.day-duration {
  margin-left: 0.5rem;
  color: var(--saffron);
}

.worksheet-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 0.9rem;
  margin: 1rem 0;
}

.worksheet-field {
  min-width: 0;
  padding-bottom: 0.3rem;
  border-bottom: 1px dashed var(--rule-strong);
  overflow-wrap: anywhere;
}

.check-row {
  position: relative;
  margin: 0.6rem 0;
  padding-left: 1.7rem;
}

.check-row::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.42em;
  width: 1rem;
  height: 1rem;
  border: 1.5px solid var(--forest);
  border-radius: 3px;
  background: var(--surface);
}

.reference-item {
  margin: 0.9rem 0;
}

.reference-title {
  margin: 0 0 0.15rem;
  font-weight: 600;
}

.reference-detail {
  margin: 0.15rem 0 0 !important;
  color: var(--muted);
  font-size: 0.92rem;
}

/* In-book table of contents */

nav[role="doc-toc"] {
  margin: 2rem 0;
  padding: 1.3rem 1.4rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

nav[role="doc-toc"] h1 {
  font-size: 1.3rem;
  margin-bottom: 0.8rem;
}

nav[role="doc-toc"] ol {
  list-style: none;
  padding-left: 0;
  columns: 2;
  column-gap: 2rem;
  font-family: var(--font-sans);
  font-size: 0.84rem;
}

nav[role="doc-toc"] ol ol {
  columns: 1;
  margin: 0.15rem 0 0.5rem 0.6rem;
  padding-left: 0.6rem;
  border-left: 1px solid var(--rule);
}

nav[role="doc-toc"] li {
  margin: 0.22rem 0;
  break-inside: avoid;
}

nav[role="doc-toc"] a {
  color: var(--ink-soft);
  text-decoration: none;
}

nav[role="doc-toc"] a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* --------------------------------------------------------------------------
   Pager + footer
   -------------------------------------------------------------------------- */

.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 clamp(1.1rem, 4vw, 2rem) 2rem;
  width: 100%;
}

.pager-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.9rem 1.05rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.pager-link:hover {
  border-color: var(--saffron-soft);
  transform: translateY(-2px);
  color: var(--ink);
}

.pager-link small {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.pager-link strong {
  font-weight: 600;
  font-size: 0.98rem;
}

.pager-next {
  grid-column: 2;
  text-align: right;
  justify-content: flex-end;
}

.pager-prev {
  grid-column: 1;
}

.site-foot {
  border-top: 1px solid var(--rule);
  background: color-mix(in oklab, var(--paper-2) 55%, transparent);
  padding: 2.4rem clamp(1.1rem, 4vw, 2rem) 2rem;
  font-family: var(--font-sans);
}

.foot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 1.6rem 2.5rem;
  max-width: 64rem;
  margin: 0 auto 1.6rem;
}

.foot-brand {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
}

.foot-note,
.foot-fine {
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.65;
  margin: 0;
}

.foot-head {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--faint);
  margin: 0 0 0.5rem;
}

.site-foot a {
  display: block;
  font-size: 0.85rem;
  margin: 0.25rem 0;
  text-decoration: none;
}

.site-foot a:hover {
  text-decoration: underline;
}

.foot-fine {
  max-width: 64rem;
  margin: 0 auto;
  padding-top: 1.3rem;
  border-top: 1px solid var(--rule);
}

/* --------------------------------------------------------------------------
   Search
   -------------------------------------------------------------------------- */

.search-dialog {
  width: min(42rem, calc(100vw - 2rem));
  max-height: min(38rem, calc(100dvh - 4rem));
  padding: 0;
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-lg);
  background: var(--surface);
  color: var(--ink);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.search-dialog::backdrop {
  background: rgba(24, 18, 12, 0.42);
  backdrop-filter: blur(3px);
}

.search-form {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 0.9rem;
  border-bottom: 1px solid var(--rule);
}

.search-icon {
  display: inline-flex;
  color: var(--muted);
}

.search-form input {
  flex: 1;
  min-width: 0;
  padding: 0.5rem 0.2rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--ink);
  background: transparent;
  border: 0;
}

.search-form input:focus {
  outline: none;
}

.search-results {
  overflow-y: auto;
  max-height: 27rem;
  padding: 0.5rem;
}

.search-empty {
  padding: 1.4rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--muted);
}

.search-item {
  display: block;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--ink);
}

.search-item:hover,
.search-item.is-active {
  background: var(--surface-2);
}

.search-item small {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--saffron);
  margin-bottom: 0.15rem;
}

.search-item strong {
  display: block;
  font-size: 0.98rem;
  font-weight: 600;
}

.search-item span {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--muted);
  margin-top: 0.15rem;
}

.search-item mark {
  background: color-mix(in oklab, var(--saffron) 30%, transparent);
  color: inherit;
  border-radius: 2px;
}

.search-hint {
  margin: 0;
  padding: 0.6rem 1rem 0.8rem;
  font-family: var(--font-sans);
  font-size: 0.74rem;
  color: var(--faint);
  border-top: 1px solid var(--rule);
}

/* --------------------------------------------------------------------------
   Landing page
   -------------------------------------------------------------------------- */

.page-landing .content,
.page-landing .pager {
  max-width: 74rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 20rem) minmax(0, 1fr);
  align-items: center;
  gap: clamp(1.8rem, 5vw, 4.5rem);
  padding: clamp(1rem, 3vw, 2.5rem) 0 clamp(2rem, 5vw, 3.5rem);
}

.hero-visual {
  perspective: 1600px;
}

.book {
  position: relative;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  transform: rotateY(-6deg) rotateX(1deg);
  transition: transform 0.5s var(--ease);
}

.book:hover {
  transform: rotateY(-2deg) rotateX(0deg) translateY(-4px);
}

.book img {
  display: block;
  width: 100%;
  border-radius: var(--radius);
}

.book::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 8%;
  border-radius: var(--radius) 0 0 var(--radius);
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.26), transparent);
  pointer-events: none;
}

.hero-copy h1 {
  font-size: clamp(2.4rem, 5vw, 3.9rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0.5rem 0 1rem;
}

.hero-copy h1 em {
  font-style: italic;
  color: var(--saffron);
}

.hero-lede {
  font-size: clamp(1.05rem, 1.2vw, 1.22rem);
  color: var(--ink-soft);
  max-width: 40ch;
  margin: 0 0 0.9rem;
}

.hero-author {
  font-family: var(--font-sans);
  font-size: 0.86rem;
  color: var(--muted);
  margin: 0 0 1.6rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease), background 0.18s var(--ease);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--ink);
  color: var(--paper);
  box-shadow: var(--shadow-sm);
}

:root[data-theme="dark"] .btn-primary {
  background: var(--saffron);
  color: #1a1410;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .btn-primary {
    background: var(--saffron);
    color: #1a1410;
  }
}

.btn-primary:hover {
  background: var(--saffron);
  color: #fff;
}

.btn-ghost {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--rule-strong);
}

.btn-ghost:hover {
  border-color: var(--saffron-soft);
  color: var(--accent);
}

.epigraph-band {
  margin: clamp(1rem, 3vw, 2rem) 0 clamp(2.5rem, 5vw, 4rem);
  padding: clamp(1.6rem, 4vw, 2.6rem);
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--paper-2), var(--surface));
  border: 1px solid var(--rule);
  text-align: center;
}

.epigraph-band blockquote {
  margin: 0;
}

.epigraph-band p {
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  font-style: italic;
  line-height: 1.7;
  margin: 0 0 0.8rem;
  color: var(--ink);
}

.epigraph-band cite {
  font-family: var(--font-sans);
  font-size: 0.76rem;
  font-style: normal;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.section {
  padding: clamp(1.6rem, 4vw, 3rem) 0;
  border-top: 1px solid var(--rule);
}

.section-title {
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  letter-spacing: -0.01em;
  margin: 0 0 0.5rem;
}

.section-lede {
  font-family: var(--font-sans);
  font-size: 0.98rem;
  color: var(--muted);
  max-width: 58ch;
  margin: 0 0 1.8rem;
}

.route {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
  counter-reset: none;
}

.route-step {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.route-step:hover {
  transform: translateY(-2px);
  border-color: var(--saffron-soft);
}

.route-link {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 0.9rem 1.1rem;
  text-decoration: none;
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 0.95rem;
}

.route-link:hover {
  color: var(--accent);
}

.route-num {
  flex: none;
  display: grid;
  place-items: center;
  width: 1.8rem;
  height: 1.8rem;
  border-radius: 50%;
  background: var(--saffron-tint);
  color: var(--saffron);
  font-weight: 700;
  font-size: 0.85rem;
}

.chapter-group {
  margin: 0 0 2rem;
}

.chapter-group-title {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--forest);
  text-decoration: none;
  margin: 0 0 0.8rem;
}

.chapter-group-title:hover {
  color: var(--saffron);
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr));
  gap: 0.75rem;
}

.chapter-card {
  display: flex;
  gap: 0.85rem;
  padding: 1rem 1.05rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.chapter-card:hover {
  transform: translateY(-3px);
  border-color: var(--saffron-soft);
  color: var(--ink);
}

.chapter-card-num {
  flex: none;
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--saffron-tint);
  color: var(--saffron);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
}

.chapter-card-num-empty {
  background: var(--forest-tint);
}

.chapter-card-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.chapter-card-text strong {
  font-size: 0.98rem;
  font-weight: 600;
  line-height: 1.35;
}

.chapter-card-deck {
  font-family: var(--font-sans);
  font-size: 0.8rem;
  color: var(--muted);
  line-height: 1.5;
  margin-top: 0.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.legend {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
  gap: 0.9rem 2rem;
}

.legend-item {
  display: flex;
  align-items: flex-start;
  gap: 0.7rem;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: var(--ink-soft);
}

.legend-item .source-badge {
  flex: none;
  margin-top: 0.15rem;
}

.related-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.2rem;
  padding: 1.3rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--forest);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.related-card:hover {
  transform: translateY(-2px);
  border-color: var(--forest);
  color: var(--ink);
}

.related-card-body {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.related-card-body strong {
  font-family: var(--font-serif);
  font-size: 1.12rem;
  font-weight: 600;
}

.related-card-body span {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--muted);
}

.related-card-url {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  flex: none;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--forest);
}

@media (max-width: 640px) {
  .related-card {
    flex-direction: column;
    align-items: flex-start;
  }
}

.boundary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr));
  gap: 0.9rem;
}

.boundary-card {
  padding: 1.2rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.boundary-card .eyebrow {
  color: var(--muted);
}

.boundary-card p {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--ink-soft);
  margin: 0.4rem 0 0;
}

.boundary-safety {
  border-color: var(--clay);
  background: var(--clay-tint);
}

.boundary-safety .eyebrow {
  color: var(--clay);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  margin-top: 0.8rem;
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 600;
  text-decoration: none;
}

/* Part index on part pages */

.part-index {
  display: grid;
  gap: 0.5rem;
  margin: 1.5rem 0 0;
  padding: 1.2rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

.part-index-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.45rem 0.55rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.92rem;
  text-decoration: none;
  color: var(--ink-soft);
}

.part-index-link:hover {
  background: var(--surface-2);
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   Scrim (mobile drawer)
   -------------------------------------------------------------------------- */

.scrim {
  position: fixed;
  inset: 0;
  z-index: 45;
  background: rgba(24, 18, 12, 0.4);
  backdrop-filter: blur(2px);
}

.scrim[hidden] {
  display: none;
}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */

@media (min-width: 1080px) {
  .layout {
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  }

  .sidebar {
    display: flex;
  }
}

@media (min-width: 1320px) {
  .layout {
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr) var(--toc-w);
  }

  .page-toc {
    display: block;
  }
}

@media (max-width: 1079px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 50;
    width: min(21rem, 86vw);
    transform: translateX(-102%);
    transition: transform 0.28s var(--ease);
    box-shadow: var(--shadow-md);
    background: var(--paper);
  }

  html[data-nav="open"] .sidebar {
    transform: translateX(0);
  }

  .sidebar-close {
    display: inline-flex;
  }

  .topbar-menu {
    display: inline-flex;
  }
}

@media (min-width: 1080px) {
  .topbar-menu {
    display: none;
  }
}

@media (max-width: 720px) {
  .hero {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-visual {
    max-width: 15rem;
    margin-inline: auto;
  }

  .book {
    transform: none;
  }

  .pager {
    grid-template-columns: 1fr;
  }

  .pager-next {
    grid-column: 1;
    text-align: left;
    justify-content: flex-start;
  }

  .decision-map,
  .concept-map,
  .concept-map-three,
  .worksheet-fields {
    grid-template-columns: minmax(0, 1fr);
  }

  .decision-wide {
    grid-column: auto;
  }

  nav[role="doc-toc"] ol {
    columns: 1;
  }

  .topbar-title {
    display: none;
  }
}

/* --------------------------------------------------------------------------
   Motion
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
  }

  .reveal.is-in {
    opacity: 1;
    transform: none;
  }
}

/* --------------------------------------------------------------------------
   Print
   -------------------------------------------------------------------------- */

@media print {
  .sidebar,
  .topbar,
  .page-toc,
  .pager,
  .reading-progress,
  .scrim,
  .site-foot,
  .search-dialog {
    display: none !important;
  }

  .layout,
  .content {
    display: block;
    max-width: none;
    padding: 0;
  }

  body {
    background: #fff;
    color: #000;
  }

  body::before {
    display: none;
  }

  a {
    color: #000;
    text-decoration: none;
  }
}