:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-muted: #f9fafb;
  --text: #111827;
  --muted: #4b5563;
  --line: #e5e7eb;
  --accent: #374151;
  --accent-muted: #f3f7f8;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.7;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(20px, 5vw, 64px);
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--line);
}

.brand {
  color: var(--text);
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 22px;
  color: var(--muted);
  font-size: 14px;
}

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

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--accent);
}

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

h1 {
  margin-bottom: 18px;
  font-size: clamp(26px, 4vw, 32px);
  line-height: 1.35;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(20px, 2.5vw, 22px);
  line-height: 1.25;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 19px;
  line-height: 1.45;
}

.section {
  max-width: 880px;
  margin: 0 auto;
  padding: clamp(36px, 7vw, 64px) clamp(20px, 5vw, 64px);
  border-top: 1px solid var(--line);
}

.section-top {
  border-top: 0;
}

.section p {
  max-width: 720px;
  color: var(--muted);
}

.plain-list {
  margin: 0;
  padding-left: 1.25em;
  color: var(--text);
}

.plain-list li + li {
  margin-top: 8px;
}

.plain-list + p {
  margin-top: 16px;
}

.company-table {
  margin: 0;
  border-top: 1px solid var(--line);
}

.company-table div {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 20px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.company-table dt {
  color: var(--muted);
  font-weight: 700;
}

.company-table dd {
  margin: 0;
}

.section-contact {
  background: var(--surface);
  color: var(--text);
}

.section-contact p {
  color: var(--muted);
}

.section-contact .company-table {
  margin-top: 20px;
}

.site-footer {
  padding: 28px clamp(20px, 5vw, 64px);
  background: var(--surface);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .company-table div {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}