.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
}

.header-inner {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0;
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-list,
.footer-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-link,
.footer-link,
.language-link {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  border-radius: 999px;
  color: var(--color-muted);
  font-size: 0.92rem;
  line-height: 1;
  padding: 0 14px;
  text-decoration: none;
}

.nav-link:hover,
.footer-link:hover,
.language-link:hover,
.nav-link[aria-current="page"] {
  background: var(--color-hover);
  color: var(--color-text);
  text-decoration: none;
}

.language-switch {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 8px;
  color: var(--color-muted);
  font-size: 0.86rem;
}

.language-current {
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  border-radius: 999px;
  background: var(--color-text);
  color: var(--color-bg);
  padding: 0 12px;
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  place-items: center;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-bg);
  cursor: pointer;
}

.menu-toggle-lines,
.menu-toggle-lines::before,
.menu-toggle-lines::after {
  display: block;
  width: 18px;
  height: 1px;
  background: var(--color-text);
  content: "";
  transition: transform 180ms ease, opacity 180ms ease;
}

.menu-toggle-lines {
  position: relative;
}

.menu-toggle-lines::before,
.menu-toggle-lines::after {
  position: absolute;
  left: 0;
}

.menu-toggle-lines::before {
  top: -6px;
}

.menu-toggle-lines::after {
  top: 6px;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines {
  background: transparent;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::before {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-lines::after {
  transform: translateY(-6px) rotate(-45deg);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-text);
  border-radius: 999px;
  background: var(--color-text);
  color: var(--color-bg);
  font-weight: 700;
  line-height: 1.1;
  padding: 0 22px;
  text-decoration: none;
}

.button:hover {
  background: #333333;
  text-decoration: none;
}

.button--secondary {
  background: var(--color-bg);
  color: var(--color-text);
}

.button--secondary:hover {
  background: var(--color-hover);
}

.card-grid {
  display: grid;
  gap: 20px;
}

.card-grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card-grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card {
  min-width: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
  padding: 28px;
}

a.card {
  transition: background 180ms ease, border-color 180ms ease, transform 180ms ease;
}

a.card:hover {
  border-color: #cccccc;
  background: var(--color-surface);
  text-decoration: none;
  transform: translateY(-2px);
}

.card p:last-child,
.project-card p:last-child {
  margin-bottom: 0;
}

.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: 40px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  color: var(--color-muted);
  font-size: 0.92rem;
}

.sns-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.sns-placeholder {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  color: var(--color-muted);
  font-size: 0.86rem;
  padding: 0 12px;
}

@media (max-width: 900px) {
  .menu-toggle {
    display: grid;
  }

  .nav {
    position: fixed;
    inset: 76px 0 auto;
    display: none;
    max-height: calc(100vh - 76px);
    overflow: auto;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-bg);
    padding: 20px;
  }

  .nav.is-open {
    display: block;
  }

  .nav-list {
    display: grid;
    gap: 6px;
  }

  .nav-link,
  .language-link,
  .language-current {
    width: 100%;
    justify-content: flex-start;
    min-height: 48px;
    border-radius: var(--radius);
  }

  .language-switch {
    margin: 14px 0 0;
    border-top: 1px solid var(--color-border);
    padding-top: 14px;
  }
}

@media (max-width: 768px) {
  .card-grid--3,
  .card-grid--2 {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }
}