:root {
  color-scheme: light;
  --bg: #f7f7f4;
  --surface: #ffffff;
  --text: #20201d;
  --muted: #62625b;
  --line: #dddcd4;
  --accent: #1d6f5f;
  --accent-strong: #134e43;
  --warm: #b4562b;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Yu Gothic", "Meiryo", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-wrap: anywhere;
}

a {
  color: inherit;
  text-decoration-color: rgba(29, 111, 95, 0.45);
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--accent-strong);
}

.site-header,
.site-footer,
main {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.site-title {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  text-decoration: none;
}

.site-title::before {
  content: "AI";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--accent);
  color: #ffffff;
  font-size: 13px;
  line-height: 1;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 16px;
  color: var(--muted);
  font-size: 14px;
}

.site-nav a {
  text-decoration: none;
}

.hero {
  display: grid;
  align-items: center;
  min-height: 54vh;
  padding: 72px 0 64px;
  border-bottom: 1px solid var(--line);
}

.hero h1,
.page-heading h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(36px, 6vw, 68px);
  line-height: 1.12;
  letter-spacing: 0;
}

.hero-copy,
.lead {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--warm);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--accent);
  border-radius: 6px;
  font-weight: 700;
  text-decoration: none;
  text-align: center;
}

.button.primary {
  background: var(--accent);
  color: #ffffff;
}

.button.secondary {
  color: var(--accent-strong);
}

.section-grid {
  display: grid;
  grid-template-columns: minmax(180px, 280px) 1fr;
  gap: 40px;
  padding: 56px 0;
  border-bottom: 1px solid var(--line);
}

.section-grid h2,
.contact-band h2 {
  margin: 0;
  font-size: 28px;
  line-height: 1.35;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.topic-grid article,
.article-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
}

.topic-grid h3,
.article-item h2,
.article-item h3 {
  margin: 0 0 10px;
  line-height: 1.4;
}

.topic-grid p,
.article-item p {
  margin: 0;
  color: var(--muted);
}

.article-list {
  display: grid;
  gap: 16px;
  padding-bottom: 56px;
}

.article-list.compact {
  padding-bottom: 0;
}

.article-item time {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
}

.page-heading {
  padding: 56px 0 36px;
}

.single {
  max-width: 860px;
}

.content {
  padding-bottom: 64px;
}

.content h2 {
  margin: 42px 0 14px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 26px;
  line-height: 1.35;
}

.content h3 {
  margin: 28px 0 10px;
  font-size: 20px;
}

.content p,
.content ul {
  margin: 0 0 18px;
}

.content li + li {
  margin-top: 6px;
}

.contact-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 48px 0;
  border-bottom: 1px solid var(--line);
}

.site-footer {
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 760px) {
  .site-header,
  .site-footer,
  main {
    width: min(100% - 28px, 1080px);
  }

  .site-header,
  .contact-band {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header {
    gap: 18px;
    padding: 20px 0;
  }

  .site-nav {
    justify-content: flex-start;
    gap: 10px 14px;
    width: 100%;
    font-size: 13px;
  }

  .hero {
    min-height: auto;
    padding: 44px 0;
  }

  .hero h1,
  .page-heading h1 {
    font-size: 34px;
    line-height: 1.18;
  }

  .hero-copy,
  .lead {
    margin-top: 18px;
    font-size: 16px;
  }

  .section-grid,
  .topic-grid {
    grid-template-columns: 1fr;
  }

  .section-grid {
    gap: 20px;
    padding: 44px 0;
  }

  .topic-grid article,
  .article-item {
    padding: 18px;
  }

  .page-heading {
    padding: 42px 0 28px;
  }

  .content {
    padding-bottom: 48px;
  }

  .content h2 {
    margin-top: 34px;
    font-size: 23px;
  }

  .content h3 {
    font-size: 18px;
  }

  .contact-band {
    padding: 38px 0;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
    line-height: 1.72;
  }

  .site-header,
  .site-footer,
  main {
    width: min(100% - 24px, 1080px);
  }

  .site-title {
    font-size: 15px;
  }

  .site-title::before {
    width: 30px;
    height: 30px;
    border-radius: 7px;
    font-size: 12px;
  }

  .site-nav {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .site-nav a {
    min-height: 38px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.55);
  }

  .hero {
    padding: 36px 0 40px;
  }

  .hero h1,
  .page-heading h1 {
    font-size: 30px;
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .button {
    min-height: 46px;
  }

  .section-grid {
    padding: 36px 0;
  }

  .section-grid h2,
  .contact-band h2 {
    font-size: 23px;
  }

  .article-list {
    gap: 12px;
    padding-bottom: 42px;
  }

  .topic-grid article,
  .article-item {
    padding: 16px;
  }

  .content ul {
    padding-left: 1.2em;
  }
}