/* ─────────────────────────────────────────
   Reset & Base
───────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #0f172a;
  color: #111827;
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.7;
}

h1, h2, h3, p, dl, dd, ul {
  margin: 0;
}

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

a:focus-visible,
button:focus-visible {
  outline: 2px solid rgba(15, 23, 42, 0.34);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ─────────────────────────────────────────
   Layout
───────────────────────────────────────── */
.container {
  width: min(100% - 48px, 1020px);
  margin: 0 auto;
}

/* ─────────────────────────────────────────
   Header
───────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 23, 42, 0.94);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  width: min(100% - 48px, 1020px);
  min-height: 62px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.brand-mark {
  width: 30px;
  height: 30px;
  display: block;
  border: 0;
  border-radius: 5px;
  background: transparent;
  object-fit: cover;
  box-shadow: 0 0 0 1px #ffffff26;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 32px;
  min-width: 0;
  flex-wrap: nowrap;
  justify-content: flex-end;
}

.site-nav a {
  padding-bottom: 3px;
  color: #cbd5e1;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color 150ms ease;
}

.site-nav a:hover {
  color: #f9fafb;
}

/* ─────────────────────────────────────────
   Hero
───────────────────────────────────────── */
.hero {
  padding: 120px 0;
  background: #0f172a;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
}

h1 {
  margin-bottom: 14px;
  font-size: clamp(36px, 5.5vw, 58px);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: #111827;
}

.hero h1 {
  color: #f9fafb;
}

.company-en {
  margin: 0 0 44px;
  color: #cbd5e1;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0;
}

/* ─────────────────────────────────────────
   Button
───────────────────────────────────────── */
.button {
  display: inline-flex;
  align-items: center;
  height: 42px;
  padding: 0 24px;
  border: 1.5px solid #f9fafb;
  border-radius: 6px;
  color: #0f172a;
  background: #f9fafb;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: background 150ms ease, color 150ms ease;
}

.button:hover {
  background: #f3f0ed;
  color: #0f172a;
}

/* ─────────────────────────────────────────
   Section — common
───────────────────────────────────────── */
.section {
  padding: 90px 0;
  border-top: 1px solid #e5e7eb;
}

.section-heading {
  margin-bottom: 48px;
}

.section-kicker {
  margin-bottom: 10px;
  color: #0f172a;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h2 {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: #111827;
}

h3 {
  margin-bottom: 10px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: #111827;
}

/* ─────────────────────────────────────────
   Business
───────────────────────────────────────── */
.business {
  background: #f9fafb;
}

.business-index {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.business-column {
  padding: 2rem;
  border-radius: 0.75rem;
  background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
  transition: all 0.3s ease;
}

.business-column:hover,
.business-column:focus-within {
  transform: translateY(-2px);
  box-shadow: 0 8px 12px rgba(0, 0, 0, 0.2);
}

.business-group-heading {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #0f172a;
}

.business-group-heading span {
  color: #0f172a;
  font-size: 1.125rem;
  font-weight: 600;
}

.business-group-heading span[aria-hidden="true"] {
  margin: 0 0.5rem;
  color: #6b7280;
}

.business-entry h3 {
  margin-bottom: 0.5rem;
  color: #0f172a;
  font-size: 1.25rem;
  font-weight: 700;
}

.business-entry p {
  margin: 0;
}

.business-entry a {
  color: #2563eb;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.2s ease;
}

.business-entry a:hover {
  color: #1d4ed8;
}

/* ─────────────────────────────────────────
   News
───────────────────────────────────────── */
.news {
  background: #f9fafb;
}

.news-list {
  list-style: none;
  padding: 0;
  border-top: 1px solid #e5e7eb;
}

.news-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 32px;
  align-items: baseline;
  padding: 22px 0;
  border-bottom: 1px solid #e5e7eb;
}

.news-date {
  color: #9ca3af;
  font-size: 13px;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.news-title {
  color: #111827;
  font-size: 15px;
  line-height: 1.6;
}

/* ─────────────────────────────────────────
   Company
───────────────────────────────────────── */
.company {
  background: #f9fafb;
}

.company-list {
  margin: 0;
  border-top: 1px solid #e5e7eb;
}

.company-list div {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 24px;
  padding: 20px 0;
  border-bottom: 1px solid #e5e7eb;
}

.company-list dt {
  color: #6b7280;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.company-list dd {
  color: #111827;
  font-size: 15px;
}

/* ─────────────────────────────────────────
   Contact
───────────────────────────────────────── */
.contact {
  background: #f9fafb;
  color: #111827;
  text-align: left;
}

.contact .section-heading {
  margin-bottom: 18px;
}

.contact h2 {
  color: #111827;
  text-align: left;
}

.contact .section-kicker {
  color: #0f172a;
}

.contact-email svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.contact-email {
  padding: 1rem 0;
}

.email-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 0.5rem;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  color: #fff;
  text-decoration: none;
  transition: all 0.3s ease;
}

.email-link:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 12px rgba(0, 0, 0, 0.2);
}

.email-link span {
  font-weight: 500;
  letter-spacing: 0.5px;
}

/* ─────────────────────────────────────────
   Footer
───────────────────────────────────────── */
.site-footer {
  padding: 28px 0;
  background: #0f172a;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: #cbd5e1;
  font-size: 13px;
}

.site-footer p {
  text-align: center;
}



/* ─────────────────────────────────────────
   404
───────────────────────────────────────── */

.error-page {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: #0f172a;
}

.error-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 0;
  min-height: calc(100vh - 140px);
}

.error-content {
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.error-text h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: #f9fafb;
  margin-bottom: 1rem;
}

.error-description {
  font-size: 1.125rem;
  color: #6b7280;
  line-height: 1.6;
  margin-bottom: 3rem;
}

.error-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 4rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  height: 42px;
  padding: 0 24px;
  border: 1.5px solid #f9fafb;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: background 150ms ease, color 150ms ease;
}

.btn-primary {
  background: #0f172a;
  color: #f9fafb;
}

.btn-primary:hover {
  background: #1e293b;
  color: #f9fafb;
}


/* ─────────────────────────────────────────
   Responsive
───────────────────────────────────────── */
@media (max-width: 860px) {
  .container,
  .header-inner {
    width: min(100% - 36px, 1100px);
  }

  .hero {
    padding: 104px 0 92px;
  }

  .section {
    padding: 76px 0;
  }

}

@media (max-width: 600px) {
  .container,
  .header-inner {
    width: min(100% - 28px, 1100px);
  }

  .site-nav {
    gap: 12px;
    flex-wrap: wrap;
    row-gap: 2px;
  }

  .site-nav a {
    font-size: 13px;
  }

  .news-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .company-list div {
    grid-template-columns: 1fr;
    gap: 4px;
    padding: 16px 0;
  }
}

@media (max-width: 480px) {
  .header-inner {
    min-height: 56px;
    gap: 16px;
  }

  .site-nav {
    gap: 8px 10px;
  }

  .site-nav a {
    font-size: 12px;
  }

  .hero {
    padding: 82px 0 72px;
  }

  .section {
    padding: 60px 0;
  }

  .section-heading {
    margin-bottom: 36px;
  }

  .mail-link {
    font-size: 20px;
  }

}