:root {
  --bg-color: #f2f2f0;
  --bg-soft: #faf8f3;
  --text-primary: #3b3a39;
  --text-secondary: #6f716d;
  --accent-color: #5c7a82;
  --accent-soft: #89a0a5;
  --accent-warm: #8d7868;
  --glass-bg: rgba(255, 255, 255, 0.6);
  --glass-strong: rgba(255, 255, 255, 0.74);
  --glass-border: rgba(255, 255, 255, 0.45);
  --shadow-soft: 0 18px 48px rgba(74, 72, 68, 0.08);
  --shadow-book: 0 28px 60px rgba(92, 122, 130, 0.18);
  --radius-xl: 30px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --content-width: min(1180px, calc(100vw - 32px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text-primary);
  font-family: "Manrope", "PingFang TC", "Microsoft JhengHei", sans-serif;
  line-height: 1.7;
  background:
    radial-gradient(circle at top left, rgba(92, 122, 130, 0.12), transparent 28%),
    radial-gradient(circle at 85% 18%, rgba(141, 120, 104, 0.14), transparent 20%),
    linear-gradient(180deg, #f7f6f2 0%, var(--bg-color) 48%, #efefea 100%);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

.page-shell {
  position: relative;
  overflow: clip;
}

.ambient {
  position: fixed;
  border-radius: 999px;
  filter: blur(18px);
  pointer-events: none;
  z-index: 0;
}

.ambient-a {
  top: 2rem;
  right: -8rem;
  width: 24rem;
  height: 24rem;
  background: radial-gradient(circle, rgba(92, 122, 130, 0.16), transparent 68%);
}

.ambient-b {
  left: -7rem;
  bottom: 10vh;
  width: 22rem;
  height: 22rem;
  background: radial-gradient(circle, rgba(141, 120, 104, 0.14), transparent 72%);
}

.hero,
.intro-section,
.contents-section,
.preview-section,
.author-section,
.cta-section {
  position: relative;
  z-index: 1;
  width: var(--content-width);
  margin: 0 auto;
}

.hero {
  min-height: 100svh;
  padding: 24px 0 80px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
}

.brand,
.top-link,
.floating-buy,
.button,
.glass-card {
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.brand,
.top-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.56);
  box-shadow: 0 12px 30px rgba(92, 122, 130, 0.08);
}

.brand-code {
  color: var(--accent-color);
  font-weight: 800;
  letter-spacing: 0.16em;
}

.brand-name,
.top-link-strong {
  font-weight: 800;
}

.top-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.top-link-strong {
  color: #fff;
  background: linear-gradient(135deg, #607d86, #7d949a);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
  gap: 32px;
  align-items: center;
  padding-top: 56px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent-color);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.hero h1,
.section-heading h2,
.hero-card h2,
.cta-copy h2 {
  margin: 0;
  font-family: "Noto Serif TC", "PingFang TC", serif;
  line-height: 1.08;
}

.hero h1 {
  font-size: clamp(3rem, 10vw, 5.25rem);
  letter-spacing: 0.04em;
}

.hero-subtitle {
  margin: 18px 0 0;
  font-size: clamp(1.15rem, 3vw, 1.65rem);
  color: var(--accent-color);
}

.hero-lead,
.section-heading p,
.intro-card p,
.cta-copy p,
.author-section p {
  color: var(--text-secondary);
}

.hero-lead {
  margin: 24px 0 0;
  max-width: 42rem;
}

.glass-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-soft);
}

.hero-card {
  margin-top: 28px;
  padding: 28px;
}

.hero-card h2 {
  font-size: clamp(1.65rem, 4vw, 2.15rem);
  margin-bottom: 12px;
}

.hero-card p {
  margin: 0;
  color: var(--text-secondary);
}

.price-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  margin-top: 28px;
}

.price-tag {
  min-width: 200px;
  padding: 18px 22px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-shadow: var(--shadow-soft);
}

.price-tag span {
  display: block;
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.price-tag strong {
  display: block;
  margin-top: 8px;
  font-size: 2rem;
  color: var(--accent-color);
}

.price-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.price-meta span {
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.45);
  color: var(--text-secondary);
  font-size: 0.94rem;
}

.hero-actions,
.cta-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.button,
.floating-buy {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 0 24px;
  border-radius: 999px;
  font-weight: 800;
  transition: transform 180ms ease, box-shadow 180ms ease, background-color 180ms ease;
}

.button:hover,
.floating-buy:hover,
.top-link:hover {
  transform: translateY(-2px);
}

.button-primary,
.floating-buy {
  color: #fff;
  background: linear-gradient(135deg, #536f77, #6f878d);
  box-shadow: 0 16px 30px rgba(92, 122, 130, 0.2);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.5);
  color: var(--text-primary);
}

.hero-visual {
  justify-self: end;
  width: min(100%, 36rem);
}

.book-stage {
  display: grid;
  place-items: center;
  min-height: 40rem;
  padding: 12px;
  background: transparent;
  border: 0;
  box-shadow: none;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.hero-book {
  width: min(100%, 31rem);
  filter: drop-shadow(0 32px 56px rgba(92, 122, 130, 0.18));
  transform: rotate(-4deg);
  will-change: transform;
}

.intro-section,
.contents-section,
.preview-section,
.author-section,
.cta-section {
  padding-top: 104px;
}

.section-heading {
  max-width: 42rem;
}

.section-heading.narrow {
  max-width: 48rem;
  margin: 0 auto;
  text-align: center;
}

.section-heading h2,
.cta-copy h2 {
  font-size: clamp(2rem, 5vw, 3.4rem);
  letter-spacing: 0.02em;
}

.section-heading p {
  margin-top: 18px;
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
  margin-top: 32px;
}

.intro-card,
.intro-visual {
  padding: 28px;
}

.intro-card p:first-child,
.intro-card p:last-child {
  margin: 0;
}

.intro-card p + p {
  margin-top: 18px;
}

.intro-visual img,
.quote-card img {
  width: 100%;
  border-radius: 18px;
  object-fit: cover;
  box-shadow: var(--shadow-book);
}

.accordion-list {
  display: grid;
  gap: 16px;
  margin-top: 32px;
}

.accordion-item {
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.44);
  background: rgba(255, 255, 255, 0.56);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.accordion-item summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 72px 1fr;
  align-items: center;
  gap: 18px;
  padding: 22px 24px;
}

.accordion-item summary::-webkit-details-marker {
  display: none;
}

.accordion-index {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: rgba(92, 122, 130, 0.12);
  color: var(--accent-color);
  font-weight: 800;
}

.accordion-title {
  font-family: "Noto Serif TC", serif;
  font-size: 1.2rem;
  font-weight: 700;
}

.accordion-panel {
  padding: 0 24px 24px 114px;
  color: var(--text-secondary);
}

.accordion-panel ul {
  margin: 0;
  padding-left: 1.2rem;
}

.accordion-panel li + li {
  margin-top: 10px;
}

.preview-strip {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 22px;
  margin-top: 32px;
  padding: 8px 0 0;
}

.preview-strip::-webkit-scrollbar {
  height: 12px;
}

.preview-strip::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.32);
  border-radius: 999px;
}

.preview-strip::-webkit-scrollbar-thumb {
  background: rgba(92, 122, 130, 0.34);
  border-radius: 999px;
}

.preview-page {
  margin: 0;
  cursor: zoom-in;
}

.preview-page:nth-child(n + 11) {
  display: none;
}

.preview-section.is-expanded .preview-page:nth-child(n + 11) {
  display: block;
}

.preview-page img {
  width: 100%;
  aspect-ratio: 3 / 4;
  height: 100%;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.52);
  box-shadow: var(--shadow-soft);
  object-fit: cover;
  object-position: top center;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.preview-page:hover img {
  transform: translateY(-4px);
  box-shadow: 0 20px 38px rgba(74, 72, 68, 0.14);
}

.preview-actions {
  display: flex;
  justify-content: center;
  margin-top: 24px;
}

.preview-toggle {
  min-height: 48px;
  padding: 0 22px;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.84);
  color: var(--text-primary);
  font: inherit;
  font-weight: 800;
  box-shadow: var(--shadow-soft);
  cursor: pointer;
}

.preview-lightbox {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;
  padding: 32px;
}

.preview-lightbox[hidden] {
  display: none;
}

.preview-lightbox-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(28, 31, 32, 0.82);
  backdrop-filter: blur(8px);
}

.preview-lightbox-figure {
  position: relative;
  z-index: 1;
  margin: 0;
  max-width: min(92vw, 920px);
  max-height: 88vh;
}

.preview-lightbox-image {
  width: auto;
  max-width: 100%;
  max-height: 88vh;
  border-radius: 24px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}

.preview-lightbox-close {
  position: absolute;
  top: 18px;
  right: 18px;
  z-index: 2;
  width: 52px;
  height: 52px;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
  color: #fff;
  font-size: 2rem;
  line-height: 1;
  cursor: pointer;
}

.insight-card {
  padding: 28px;
}

.insight-spotlight {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(300px, 0.95fr);
  align-items: center;
  gap: 24px;
  margin-top: 32px;
}

.insight-copy {
  text-align: left;
}

.insight-kicker {
  margin: 0 0 12px;
  color: var(--accent-color);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

.insight-card h3 {
  margin: 0 0 12px;
  font-family: "Noto Serif TC", serif;
  font-size: 1.45rem;
  line-height: 1.4;
}

.insight-card p {
  margin: 0;
  color: var(--text-secondary);
}

.insight-card p + p {
  margin-top: 16px;
}

.insight-visual {
  margin: 0;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

.insight-visual img {
  width: min(100%, 38rem);
  height: auto;
  object-fit: contain;
}

.cta-section {
  display: grid;
  gap: 24px;
  padding-bottom: 88px;
}

.cta-copy {
  max-width: 44rem;
}

.floating-buy {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 5;
  opacity: 0;
  pointer-events: none;
}

.floating-buy.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.reveal {
  opacity: 1;
  transform: none;
}

@media (max-width: 960px) {
  .hero-grid,
  .intro-grid,
  .insight-spotlight {
    grid-template-columns: 1fr;
  }

  .preview-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .hero-visual {
    justify-self: stretch;
  }

  .book-stage {
    min-height: 28rem;
  }

  .section-heading h2,
  .cta-copy h2 {
    max-width: 14ch;
  }

  .insight-visual {
    justify-content: center;
  }
}

@media (max-width: 768px) {
  .hero {
    padding-bottom: 64px;
  }

  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .top-actions {
    justify-content: stretch;
  }

  .top-actions a,
  .brand {
    justify-content: center;
  }

  .hero-grid {
    padding-top: 34px;
    gap: 24px;
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .hero-subtitle {
    font-size: 1.08rem;
  }

  .hero-card,
  .intro-card,
  .intro-visual,
  .insight-card {
    padding: 22px;
  }

  .book-stage {
    min-height: 0;
    padding: 20px;
  }

  .accordion-item summary {
    grid-template-columns: 54px 1fr;
    gap: 14px;
    padding: 18px;
  }

  .accordion-index {
    width: 44px;
    height: 44px;
  }

  .accordion-title {
    font-size: 1.02rem;
  }

  .accordion-panel {
    padding: 0 18px 20px 18px;
  }

  .preview-strip {
    grid-template-columns: none;
    grid-auto-flow: column;
    grid-auto-columns: 86vw;
    gap: 14px;
    padding: 0 2px 12px;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
  }

  .preview-page {
    cursor: default;
    scroll-snap-align: center;
  }

  .preview-page:nth-child(n + 11),
  .preview-section.is-expanded .preview-page:nth-child(n + 11) {
    display: block;
  }

  .preview-page img {
    aspect-ratio: auto;
    height: auto;
    object-fit: initial;
  }

  .preview-actions,
  .preview-lightbox {
    display: none;
  }
}