:root {
  --ink: #363a3a;
  --muted: #626a69;
  --mint: #dff2e9;
  --mint-dark: #28715c;
  --yellow: #fff0b8;
  --yellow-dark: #745715;
  --cream: #fffcf4;
  --line: #dfe6e2;
  --white: #fff;
  --radius: 20px;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", YuGothic, Meiryo, sans-serif;
  color: var(--ink);
  background: var(--white);
  font-synthesis: none;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  font-size: 16px;
  line-height: 1.75;
  overflow-wrap: anywhere;
}

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

p, figure { margin: 0; }

h1, h2, h3 {
  margin: 0;
  line-height: 1.4;
  letter-spacing: .03em;
}

h1 { font-size: clamp(1.75rem, 7.5vw, 2.75rem); }
h2 { font-size: clamp(1.45rem, 6vw, 2rem); }

.container {
  width: min(100% - 32px, 960px);
  margin-inline: auto;
}

.brand-name {
  font-size: .78rem;
  font-weight: 800;
  letter-spacing: .13em;
}

.hero {
  padding: 36px 0 56px;
  text-align: center;
  background: var(--cream);
}

.hero-header { margin-bottom: 28px; }
.series-name { font-size: .78rem; color: var(--muted); }

.hero-message {
  margin-bottom: 6px;
  color: var(--mint-dark);
  font-weight: 800;
  letter-spacing: .06em;
}

.hero-description {
  display: grid;
  gap: 8px;
  margin: 18px auto 28px;
  max-width: 600px;
  color: var(--muted);
}

.hero-previews {
  display: grid;
  gap: 16px;
  max-width: 700px;
  margin-inline: auto;
}

.preview-card {
  padding: 14px 14px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.preview-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: contain;
  border-radius: 12px;
}

.preview-card--mint img { background: var(--mint); }
.preview-card--yellow img { background: var(--yellow); }

.preview-card figcaption {
  padding-top: 9px;
  font-weight: 700;
}

.download-section { padding: 64px 0; }
.download-section--tinted { background: var(--cream); }

.resource-grid {
  display: grid;
  gap: 28px;
  align-items: center;
}

.resource-copy { text-align: center; }

.section-label {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 12px;
  border-radius: 999px;
  color: var(--mint-dark);
  background: var(--mint);
  font-size: .82rem;
  font-weight: 800;
}

.section-label--yellow { color: var(--yellow-dark); background: var(--yellow); }
.resource-copy > p:not(.section-label) { margin: 12px 0 22px; color: var(--muted); }

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 56px;
  padding: 13px 20px;
  border: 2px solid var(--mint-dark);
  border-radius: 14px;
  color: var(--white);
  background: var(--mint-dark);
  font-weight: 800;
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
}

.button--yellow {
  border-color: var(--yellow-dark);
  color: var(--white);
  background: var(--yellow-dark);
}

.button:hover { filter: brightness(.94); }
.button:focus-visible { outline: 4px solid #ef7e69; outline-offset: 3px; }

.resource-preview {
  padding: 18px;
  border-radius: var(--radius);
}

.resource-preview--mint { background: var(--mint); }
.resource-preview--yellow { background: var(--yellow); }

.resource-preview img {
  width: 100%;
  max-height: 540px;
  object-fit: contain;
  border-radius: 10px;
}

.steps-section { padding: 64px 0; }
.steps-section h2 { margin-bottom: 28px; text-align: center; }

.steps-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps-list li {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 14px;
  align-items: center;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
}

.step-number {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  border-radius: 50%;
  color: var(--mint-dark);
  background: var(--mint);
  font-size: 1.2rem;
  font-weight: 800;
}

.steps-list h3 { font-size: 1.05rem; }
.steps-list p { color: var(--muted); font-size: .93rem; line-height: 1.55; }

.site-footer {
  padding: 44px 0 32px;
  color: #4b5352;
  background: #edf4f0;
  text-align: center;
}

.site-footer .book-title { margin-top: 4px; font-weight: 700; }
.notice { margin-top: 24px; font-size: .82rem; }
.copyright { margin-top: 22px; font-size: .78rem; }

.home-page { background: var(--cream); }
.home-main {
  display: grid;
  min-height: 100vh;
  padding: 24px;
  place-content: center;
  gap: 24px;
  text-align: center;
}
.home-main .button { max-width: 360px; }

@media (min-width: 600px) {
  .hero { padding: 48px 0 72px; }
  .hero-previews { grid-template-columns: repeat(2, 1fr); }
  .resource-grid { grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: 56px; }
  .resource-grid--reverse .resource-copy { order: 2; }
  .resource-copy { text-align: left; }
  .button { width: auto; min-width: 280px; }
  .steps-list { grid-template-columns: repeat(3, 1fr); gap: 16px; }
  .steps-list li { grid-template-columns: 1fr; align-content: start; text-align: center; }
  .step-number { margin-inline: auto; }
}

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