/* ---------- Header ---------- */
.site-header {
  background: var(--color-surface);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.site-header__logo img { display: block; }

.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 110;
}

.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.site-nav {
  position: fixed;
  inset: 64px 0 0 0;
  background: var(--color-surface);
  transform: translateX(100%);
  transition: transform 0.25s ease;
  overflow-y: auto;
}

.site-nav.is-open { transform: translateX(0); }

.site-nav__list {
  list-style: none;
  margin: 0;
  padding: var(--space-6) var(--space-4);
}

.site-nav__list li + li { margin-top: var(--space-2); }

.site-nav__list a {
  display: block;
  padding: var(--space-3) var(--space-2);
  color: var(--color-text);
  font-weight: 700;
  border-bottom: 1px solid var(--color-border-light);
}

.site-nav__list a[aria-current="page"] { color: var(--color-primary); }

@media (min-width: 900px) {
  .nav-toggle { display: none; }

  .site-nav {
    position: static;
    inset: auto;
    transform: none;
    background: none;
    overflow: visible;
  }

  .site-nav__list {
    display: flex;
    gap: var(--space-6);
    padding: 0;
  }

  .site-nav__list li + li { margin-top: 0; }

  .site-nav__list a {
    padding: var(--space-2) 0;
    border-bottom: none;
  }
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-accent);
  color: #fff;
  margin-top: var(--space-8);
  padding: var(--space-7) 0 var(--space-5);
}

.site-footer__inner { display: grid; gap: var(--space-6); }

.site-footer a { color: #fff; }

.site-footer__brand {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.site-footer__brand p {
  margin: 0;
  opacity: 0.85;
  white-space: nowrap;
  font-size: clamp(0.56rem, 1.9vw, 0.95rem);
}

.site-footer__heading {
  margin: 0 0 var(--space-3);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  opacity: 0.6;
}

.site-footer__nav ul,
.site-footer__legal ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.site-footer__legal ul { font-size: 0.85rem; opacity: 0.85; }

.site-footer__copyright {
  margin: 0;
  font-size: 0.8rem;
  opacity: 0.7;
}

@media (min-width: 900px) {
  .site-footer__inner {
    /* ロゴ+タグラインは専有の1行(全カラム幅)とし、サイトマップ等の3カラムと領域が重ならないようにする */
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1fr) minmax(0, 1.3fr);
    align-items: start;
  }
  .site-footer__brand {
    grid-column: 1 / -1;
  }
  .site-footer__copyright {
    grid-column: 1 / -1;
    text-align: center;
    margin-top: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid rgba(255, 255, 255, 0.15);
  }
}

/* ---------- Generic sections ---------- */
.section { padding: var(--space-8) 0; }
.section--alt { background: var(--color-surface); }