:root {
  --ink: #222222;
  --muted: #5e625f;
  --green: #1f3a34;
  --green-2: #2d5149;
  --paper: #f7f1e6;
  --paper-2: #fffaf0;
  --gold: #c89b3c;
  --line: #ded6c8;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper-2);
  font-family: Arial, "Microsoft JhengHei", sans-serif;
  line-height: 1.7;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px min(5vw, 56px);
  background: rgba(255, 250, 240, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  color: var(--paper-2);
  background: var(--green);
  border-radius: 8px;
  font-weight: 700;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  color: var(--muted);
  font-size: 14px;
}

.nav a:hover,
.featured-post a:hover,
.book-slot:hover strong {
  color: var(--green);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  align-items: center;
  gap: min(6vw, 72px);
  min-height: 560px;
  padding: 64px min(6vw, 72px);
  background: var(--paper);
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 18px;
  color: var(--green);
  font-size: clamp(40px, 7vw, 72px);
  line-height: 1.08;
}

h2 {
  margin-bottom: 18px;
  color: var(--green);
  font-size: 32px;
  line-height: 1.25;
}

h3 {
  margin-bottom: 12px;
  font-size: 24px;
  line-height: 1.35;
}

.lead {
  max-width: 680px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border: 1px solid var(--green);
  border-radius: 8px;
  color: var(--green);
  font-weight: 700;
}

.button.primary {
  color: var(--paper-2);
  background: var(--green);
}

.hero-visual {
  display: grid;
  min-height: 360px;
  place-items: center;
}

.book-cover {
  width: min(100%, 340px);
  aspect-ratio: 3 / 4;
  padding: 34px;
  color: var(--paper-2);
  background: var(--green);
  border: 10px solid var(--green-2);
  border-radius: 8px;
  box-shadow: 18px 20px 0 rgba(31, 58, 52, 0.16);
}

.book-cover span,
.book-cover strong,
.book-cover small {
  display: block;
}

.book-cover span {
  color: var(--gold);
  font-size: 22px;
}

.book-cover strong {
  margin-top: 8px;
  font-size: 64px;
  line-height: 1;
}

.book-cover small {
  margin-top: 160px;
  color: #eadfca;
}

.section {
  padding: 64px min(6vw, 72px);
}

.section-heading {
  max-width: 760px;
}

.featured-post {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  max-width: 980px;
  padding: 28px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.post-meta {
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 14px;
}

.read-more {
  flex: 0 0 auto;
  color: var(--green);
  font-weight: 700;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.books-section {
  background: #fbf6ed;
}

.book-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
}

.book-slot {
  min-height: 170px;
  padding: 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.book-slot span,
.book-slot strong {
  display: block;
}

.book-slot span {
  margin-bottom: 12px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.book-slot strong {
  margin-bottom: 8px;
  color: var(--green);
  font-size: 18px;
}

.book-slot p {
  color: var(--muted);
  font-size: 14px;
}

.topic {
  min-height: 160px;
  padding: 22px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.topic strong,
.topic span {
  display: block;
}

.topic strong {
  margin-bottom: 10px;
  color: var(--green);
  font-size: 20px;
}

.topic span,
.split p,
.channel-card p,
.steps span {
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 420px);
  gap: 32px;
  background: var(--paper);
}

.channel-card {
  padding: 26px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.channel-card strong {
  display: block;
  margin-bottom: 12px;
  color: var(--green);
  font-size: 22px;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  padding: 0;
  list-style: none;
}

.steps li {
  padding: 22px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.steps strong,
.steps span {
  display: block;
}

.steps strong {
  margin-bottom: 8px;
  color: var(--green);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px min(6vw, 72px);
  color: var(--paper);
  background: var(--green);
}

.site-footer p {
  margin: 0;
}

.article {
  max-width: 860px;
  margin: 0 auto;
}

.article h1 {
  font-size: clamp(36px, 6vw, 60px);
}

.article p {
  font-size: 18px;
}

@media (max-width: 880px) {
  .site-header,
  .hero,
  .split,
  .site-footer {
    display: block;
  }

  .nav {
    margin-top: 16px;
  }

  .hero {
    min-height: auto;
  }

  .hero-visual {
    margin-top: 36px;
  }

  .topic-grid,
  .steps,
  .book-list {
    grid-template-columns: 1fr;
  }

  .featured-post {
    display: block;
  }
}