* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Noto Sans JP', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  color: #111827;
  background-color: #ffffff;
  display: grid;
  grid-template-rows: auto 1fr;
}

body.menu-open {
  overflow: hidden;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1.75rem 1.5rem 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 3;
  pointer-events: none;
}

.menu-toggle {
  position: absolute;
  left: 1.5rem;
  top: 1.75rem;
  display: inline-flex;
  flex-direction: column;
  justify-content: space-between;
  width: 26px;
  height: 20px;
  border: none;
  background: none;
  padding: 0;
  cursor: pointer;
  color: #111827;
  pointer-events: auto;
}

.menu-toggle:focus-visible {
  outline: 2px solid #2563eb;
  outline-offset: 4px;
}

.menu-toggle .bar {
  height: 2px;
  width: 100%;
  background-color: currentColor;
  transition: transform 0.25s ease, opacity 0.25s ease, background-color 0.25s ease;
}

.menu-toggle.is-open .bar:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}

.menu-toggle.is-open .bar:nth-child(2) {
  opacity: 0;
}

.menu-toggle.is-open .bar:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

.menu-toggle.is-open .bar {
  background-color: #f8fafc;
}

.logo-stage {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 0 1.5rem 3rem;
}

.logo {
  width: min(160px, 60vw);
  max-width: 240px;
  height: auto;
}

.site-nav {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.94);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  z-index: 2;
}

.site-nav.open {
  display: flex;
}

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  text-align: center;
}

.site-nav li + li {
  margin-top: 1.5rem;
}

.site-nav a {
  color: #f8fafc;
  text-decoration: none;
  font-size: 1.35rem;
  letter-spacing: 0.1em;
}

@media (min-width: 768px) {
  .site-header {
    padding: 2rem 2.5rem 0;
  }

  .menu-toggle {
    left: 2.5rem;
    top: 2rem;
    width: 28px;
    height: 22px;
  }

  .logo {
    width: min(200px, 30vw);
  }
}