/* ==========================================================================
   THG Brand Book — book.css
   Page chrome + brand book-specific layout.
   Light-theme canonical. Matches thgadvisor.com posture:
   - White canvas
   - Lavender-gray (#D8DBE5) sunken bands
   - 12px rounded section corners
   - Dark midnight footer
   - No weird gradient backgrounds anywhere
   ========================================================================== */


/* ----- Page shell ------------------------------------------------------ */
.book {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  min-height: 100vh;
  background: var(--color-surface);
}
@media (max-width: 1279px) {
  .book { grid-template-columns: 1fr; }
}


/* ----- Header (top, sticky, full-width) -------------------------------- */
.book-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--nav-bg);
  backdrop-filter: var(--nav-blur);
  -webkit-backdrop-filter: var(--nav-blur);
  border-bottom: var(--nav-border);
  grid-column: 1 / -1;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  padding-inline: var(--gutter);
}
.book-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--space-24);
}
.book-header__brand {
  display: flex;
  align-items: center;
  gap: var(--space-12);
  color: var(--color-heading);
  text-decoration: none;
}
.book-header__brand:hover { color: var(--color-heading); }
.book-header__brand img { height: 34px; width: auto; }
.book-header__type {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  line-height: 1.2;
  letter-spacing: 0.06em;
  color: var(--color-text-subtle);
  text-transform: uppercase;
  font-weight: var(--fw-semibold);
}
.book-header__type strong {
  color: var(--color-heading);
  font-weight: var(--fw-bold);
  font-family: var(--font-sans);
  font-size: var(--fs-body-s);
  letter-spacing: -0.005em;
  text-transform: none;
}
.book-header__nav {
  display: flex;
  gap: var(--space-32);
  align-items: center;
}
@media (max-width: 1279px) {
  .book-header__nav { display: none; }
}
.book-header__nav a {
  font-size: var(--fs-body-s);
  color: var(--color-text);
  text-decoration: none;
  font-weight: var(--fw-medium);
  transition: color var(--duration-fast) var(--ease-standard);
}
.book-header__nav a:hover,
.book-header__nav a.is-current { color: var(--color-brand-text); }

.book-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-12);
}
.book-header__updated {
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
  font-weight: var(--fw-semibold);
}
@media (max-width: 760px) { .book-header__updated { display: none; } }

.theme-toggle {
  width: 40px; height: 40px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border);
  color: var(--color-heading);
  display: inline-flex; align-items: center; justify-content: center;
  transition: border-color var(--duration-fast) var(--ease-standard), background-color var(--duration-fast) var(--ease-standard);
  background: var(--color-surface);
}
.theme-toggle:hover { border-color: var(--color-border-strong); background: var(--color-surface-sunken); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .moon { display: block; }
.theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .moon { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: block; }


/* ----- Side nav ------------------------------------------------------- */
.book-side {
  border-right: var(--hairline);
  padding: var(--space-32) var(--space-24);
  position: sticky;
  top: var(--nav-height);
  align-self: start;
  height: calc(100vh - var(--nav-height));
  overflow-y: auto;
  background: var(--c-paper-50);
}
@media (max-width: 1279px) {
  .book-side { display: none; }
}
.book-side__title {
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-caption);
  text-transform: uppercase;
  font-weight: var(--fw-bold);
  color: var(--color-text-subtle);
  margin-bottom: var(--space-16);
}
.book-side__list { list-style: none; padding: 0; margin: 0; }
.book-side__list li { margin: 0; }
.book-side__link {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: var(--space-8);
  padding: var(--space-12);
  border-radius: var(--radius-sm);
  font-size: var(--fs-body-s);
  color: var(--color-text);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: background-color var(--duration-fast) var(--ease-standard), color var(--duration-fast) var(--ease-standard), border-color var(--duration-fast) var(--ease-standard);
  font-weight: var(--fw-medium);
}
.book-side__link:hover {
  background: var(--color-surface);
  color: var(--color-heading);
}
.book-side__link.is-current {
  color: var(--color-heading);
  border-left-color: var(--color-brand);
  background: var(--color-surface);
}
.book-side__num {
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.06em;
  color: var(--color-text-subtle);
  font-weight: var(--fw-bold);
}
.book-side__link.is-current .book-side__num { color: var(--color-brand-text); }


/* ----- Main content area --------------------------------------------- */
.book-main {
  padding-inline: var(--gutter);
  padding-bottom: var(--space-128);
  min-width: 0;
}
.book-main > section {
  max-width: 1080px;
  margin-inline: auto;
  padding-block: var(--space-section);
  scroll-margin-top: calc(var(--nav-height) + 24px);
}

/* Tinted sections use lavender-gray surface AND the live site's rounded
   section corners (12px). They extend edge-to-edge inside the content column
   with breathing room. */
.book-main > section.section-tinted {
  max-width: none;
  background: var(--color-surface-sunken);
  border-radius: var(--section-radius);
  padding-inline: var(--gutter);
  margin-inline: 0;
  margin-block: var(--space-48);
}
.book-main > section.section-tinted .section-inner {
  max-width: 1080px;
  margin-inline: auto;
  padding-block: var(--space-section);
}
.book-main > section.section-tinted > .section-inner { padding-block: 0; }

.section-head { margin-bottom: var(--space-48); }
.section-head h2 {
  margin-top: var(--space-12);
  color: var(--color-heading);
}
.section-head .lead {
  font-size: var(--fs-body-l);
  line-height: var(--lh-body-l);
  color: var(--color-text);
  margin-top: var(--space-16);
  max-width: 64ch;
}


/* ----- Cover (no weird gradient — clean white with structural rhythm) - */
.cover {
  position: relative;
  isolation: isolate;
  min-height: calc(100vh - var(--nav-height));
  display: grid;
  grid-template-rows: 1fr auto;
  gap: var(--space-32);
  padding-block: var(--space-section-lg);
  background: var(--color-surface);
}
.cover__inner {
  max-width: 1080px;
  margin-inline: auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--space-32);
}
.cover__mark img { height: 56px; width: auto; }
.cover h1 {
  font-size: var(--fs-display-xl);
  line-height: var(--lh-display-xl);
  letter-spacing: var(--tracking-display);
  font-weight: var(--fw-bold);
  max-width: 18ch;
  color: var(--color-heading);
}
.cover__sub {
  font-size: var(--fs-body-l);
  line-height: var(--lh-body-l);
  color: var(--color-text);
  max-width: 64ch;
}
.cover__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-8);
  margin-top: var(--space-24);
}
.cover__scroll {
  display: inline-flex;
  align-items: center;
  gap: var(--space-8);
  color: var(--color-text-subtle);
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-caption);
  text-transform: uppercase;
  font-weight: var(--fw-semibold);
  text-decoration: none;
  margin-top: var(--space-48);
}
.cover__scroll:hover { color: var(--color-brand-text); }


/* ----- Block grids --------------------------------------------------- */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-24); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-24); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-16); }
.grid-5 { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--space-12); }
.grid-6 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-24); }
@media (max-width: 880px) {
  .grid-3, .grid-4, .grid-6 { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-6 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(2, 1fr); }
}


/* ----- Statement card ------------------------------------------------ */
.statement {
  background: var(--color-surface);
  border-radius: var(--card-radius);
  padding: var(--card-padding);
  position: relative;
  box-shadow: var(--card-shadow);
}
.statement__lead {
  font-family: var(--font-display);
  font-size: var(--fs-display-m);
  line-height: var(--lh-display-m);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--fw-semibold);
  color: var(--color-heading);
}
.statement__lead em {
  color: var(--color-brand-text);
  font-style: normal;
}
.statement__meta {
  display: flex;
  gap: var(--space-12);
  margin-top: var(--space-24);
  align-items: center;
  flex-wrap: wrap;
}


/* ----- Do / Don't pair (clean — NO weird gradients) ------------------ */
.dod {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-24);
}
@media (max-width: 760px) { .dod { grid-template-columns: 1fr; } }
.dod__panel {
  border-radius: var(--card-radius);
  padding: var(--space-32);
  background: var(--color-surface);
  box-shadow: var(--card-shadow);
  border-top: 4px solid var(--color-border);
}
.dod__panel--do { border-top-color: var(--color-brand); }
.dod__panel--dont { border-top-color: var(--color-danger); }
.dod__label {
  display: inline-block;
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-caption);
  text-transform: uppercase;
  font-weight: var(--fw-bold);
  margin-bottom: var(--space-16);
}
.dod__panel--do .dod__label { color: var(--color-brand-text); }
.dod__panel--dont .dod__label { color: var(--color-danger); }
.dod__panel ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.dod__panel li {
  padding-left: var(--space-24);
  position: relative;
  color: var(--color-heading);
  font-size: var(--fs-body-s);
  line-height: 1.65;
  margin-block: var(--space-8);
}
.dod__panel--do li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-brand);
  font-weight: var(--fw-bold);
}
.dod__panel--dont li::before {
  content: "✕";
  position: absolute;
  left: 0;
  color: var(--color-danger);
  font-weight: var(--fw-bold);
}


/* ----- Swatch tiles --------------------------------------------------- */
.swatch {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-radius: var(--card-radius);
  overflow: hidden;
  background: var(--color-surface);
  cursor: pointer;
  text-align: left;
  transition: transform var(--duration-fast) var(--ease-standard), box-shadow var(--duration-fast) var(--ease-standard);
  width: 100%;
  box-shadow: var(--card-shadow);
  border: 0;
}
.swatch:hover { transform: translateY(-2px); box-shadow: var(--card-shadow-hover); }
.swatch__chip {
  height: 96px;
  width: 100%;
  display: block;
}
.swatch__body {
  padding: var(--space-12) var(--space-16);
  display: grid;
  gap: 2px;
}
.swatch__name {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  color: var(--color-heading);
  word-break: break-all;
}
.swatch__hex {
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.swatch-ramp {
  display: grid;
  grid-template-columns: repeat(11, 1fr);
  gap: 6px;
  margin-bottom: var(--space-16);
}
@media (max-width: 880px) { .swatch-ramp { grid-template-columns: repeat(6, 1fr); } }
.swatch-step {
  height: 64px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 0;
  font-family: var(--font-mono);
  font-size: 10px;
  color: rgba(0,0,0,0.55);
  display: flex;
  align-items: end;
  justify-content: start;
  padding: 4px 6px;
  transition: transform var(--duration-fast) var(--ease-standard);
}
.swatch-step:hover { transform: scale(1.04); }


/* ----- Tables -------------------------------------------------------- */
.tbl {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-body-s);
}
.tbl th, .tbl td {
  text-align: left;
  padding: var(--space-12) var(--space-16);
  border-bottom: var(--hairline);
  vertical-align: top;
}
.tbl th {
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-caption);
  text-transform: uppercase;
  color: var(--color-text-subtle);
  font-weight: var(--fw-bold);
  background: var(--c-paper-50);
}
.tbl td { color: var(--color-heading); }
.tbl td.mono { font-family: var(--font-mono); font-size: var(--fs-mono-s); color: var(--color-heading); }
.tbl tr:last-child td { border-bottom: 0; }
.tbl tr:hover td { background: var(--c-paper-50); }
.tbl-wrap {
  border-radius: var(--card-radius);
  overflow: hidden;
  background: var(--color-surface);
  box-shadow: var(--card-shadow);
}


/* ----- Contrast cell ------------------------------------------------- */
.contrast {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-12);
  align-items: center;
  padding: var(--space-16) var(--space-24);
  border-radius: var(--card-radius);
  box-shadow: var(--card-shadow);
}
.contrast__sample { font-size: var(--fs-body-s); font-weight: var(--fw-semibold); }
.contrast__meta {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  display: flex; flex-direction: column; align-items: end;
}
.contrast__badge {
  font-size: 10px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  border: 1px solid currentColor;
  margin-top: 4px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: var(--fw-bold);
}


/* ----- Type sample --------------------------------------------------- */
.type-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--space-32);
  padding-block: var(--space-24);
  border-top: var(--hairline);
  align-items: baseline;
}
.type-row:first-child { border-top: 0; }
.type-row__meta {
  font-family: var(--font-mono);
  font-size: var(--fs-mono-s);
  color: var(--color-text-subtle);
  display: flex; flex-direction: column; gap: 4px;
}
.type-row__meta strong {
  color: var(--color-heading);
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  text-transform: uppercase;
  letter-spacing: var(--tracking-caption);
}
.type-row__sample { color: var(--color-heading); }
@media (max-width: 760px) {
  .type-row { grid-template-columns: 1fr; }
}


/* ----- Code panel ---------------------------------------------------- */
.code {
  background: var(--c-paper-100);
  border-radius: var(--card-radius);
  position: relative;
}
.code pre {
  margin: 0;
  padding: var(--space-16) var(--space-24);
  background: transparent;
  border: 0;
  border-radius: 0;
  overflow-x: auto;
  font-size: var(--fs-mono-s);
  line-height: 1.65;
  color: var(--color-heading);
}
.code__copy {
  position: absolute;
  top: 10px;
  right: 10px;
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.04em;
  color: var(--color-text);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-pill);
  padding: 4px 14px;
  background: var(--color-surface);
  cursor: pointer;
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
}
.code__copy:hover { color: var(--color-heading); border-color: var(--color-heading); }


/* ----- Logo demo tiles ----------------------------------------------- */
.logo-tile {
  border-radius: var(--card-radius);
  padding: var(--space-48) var(--space-32);
  display: flex; align-items: center; justify-content: center;
  min-height: 200px;
  box-shadow: var(--card-shadow);
}
.logo-tile--light { background: var(--color-surface); }
.logo-tile--sunken { background: var(--color-surface-sunken); }
.logo-tile--dark { background: var(--c-midnight-700); }
.logo-tile--brand { background: var(--color-brand); }
.logo-tile img { height: 56px; width: auto; }
.logo-tile--light img { filter: brightness(0); }
.logo-tile--sunken img { filter: brightness(0); }
.logo-tile--dark img { filter: brightness(0) invert(1); }
.logo-tile--brand img { filter: brightness(0) invert(1); }

.logo-meta {
  display: flex;
  justify-content: space-between;
  gap: var(--space-12);
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-weight: var(--fw-semibold);
  color: var(--color-text-subtle);
  padding-top: var(--space-12);
}


/* ----- Toast --------------------------------------------------------- */
.toast {
  position: fixed;
  bottom: var(--space-24);
  right: var(--space-24);
  background: var(--c-midnight-700);
  color: var(--color-surface);
  padding: var(--space-12) var(--space-24);
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: var(--fs-body-s);
  font-weight: var(--fw-medium);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity var(--duration-base) var(--ease-standard), transform var(--duration-base) var(--ease-standard);
  pointer-events: none;
  z-index: 50;
}
.toast.is-visible { opacity: 1; transform: translateY(0); }


/* ----- Footer (dark — matches live site) ----------------------------- */
.book-footer {
  grid-column: 1 / -1;
  padding: var(--space-48) var(--gutter);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-16);
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: var(--fw-semibold);
  color: var(--c-paper-400);
  flex-wrap: wrap;
  background: var(--c-midnight-700);
}
.book-footer a { color: var(--c-paper-300); text-decoration: none; }
.book-footer a:hover { color: var(--color-surface); }


/* ----- Cross-link strip ---------------------------------------------- */
.crosslinks {
  display: flex;
  gap: var(--space-32);
  flex-wrap: wrap;
  border-top: var(--hairline);
  padding-top: var(--space-24);
  margin-top: var(--space-48);
  color: var(--color-text-subtle);
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-weight: var(--fw-bold);
  align-items: center;
}


/* ----- Persona card -------------------------------------------------- */
.persona {
  display: flex;
  flex-direction: column;
  gap: var(--space-12);
  height: 100%;
}
.persona__quote {
  margin-top: var(--space-16);
  padding-top: var(--space-16);
  border-top: var(--hairline);
  font-style: italic;
  color: var(--color-heading);
  font-size: var(--fs-body-s);
  line-height: 1.6;
}
.persona__quote-label {
  font-family: var(--font-accent);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-caption);
  text-transform: uppercase;
  font-weight: var(--fw-bold);
  color: var(--color-text-subtle);
  display: block;
  margin-bottom: var(--space-8);
  font-style: normal;
}